A  Talk  on  Weeds 


LIBRARY 

THE  UNIVERSITY 
OF  CALIFORNIA 

SANTA  BARBARA 

PRESENTED  BY 

F.E.    CLEMENTS 


A  Talk  on  Weeds 


An  address  delivered  before  the  County 
Road  School,  Clinton  County,  Iowa,  1910, 
with  an  appendix  describing  a  few  weeds 


BY 

L.  H.    PAMMEL,  PH.  D. 

PROFESSOR  OF  BOTANY,  IOWA  STATE  COLLEGE 
AMES,  IOWA. 


Copyright  1910  by 
L.  H.  Pammel 


Table  of  Contents 


PAGE 

What  is  a  Weed,  Kinds  of  Weeds,  Annual,  Winter  Annual 5 

Biennial,  Perennial,  How  Weeds  Spread,  Vegetative  Propagration. . .  6 

Seed  Propagation,  Dissemination  or  Scattering  of  Plants 7 

Water,    Animals 8 

Explosive  Properties,  Seeds  Burying  Themselves 9 

Man  as  an  Agent,  Impure  Seeds 10 

Iowa   Pure   Seed   Law 11 

Threshing  Machines,  Cultivation,  Packing  Material,  Plants,  Culti- 
vated for  Ornamental  Purposes,  Iowa  Weed  Law 16 

Other  Weeds,  Treatment  of  Weeds 20 

Perennial    Weeds 21 

Quack  Grass,  The  Cover  Method,  Canada  Thistle  and  Horse  Nettle. .  .22 

Morning  Glory  and  Milk  Weed 23 

Indian   Mallow 24 

Sweet  Clover,  Greater  Ragweed  or  Kinghead,  Cocklebur 25 

Weeds  of  Special  Crops,  Small  Grain,  Corn 26 

Garden  Weeds,  Meadows,  Pastures,  Roadsides,  Poisonous  Weeds 27 

Grass  Family,  Yellow  Foxtail 30 

Green  Foxtail,  Quack  Grass 31 

Drop  Seed  Grass,  Squirreltail  Grass 33 

Crab  Grass,  Sedge  Family,  Dock  and  Smartweed 34 

Curled    Dock 35 

Pale  Dock,   Sheep  Sorrel 36 

Goosefoot  Family,  Pigweed  Family,  Pink  Family 37 

Purslane   Family 38 

Crowfoot   Family,   Mustard   Family 40 

Mallow    Family 41 

Velvet  Weed,  Parsley  Family 42 

Parsnip,    Carrot 43 

Oowbane    44 

Morning  Glory,  Dodder 45 

Mint    Family 47 

Nightshade,    Horse   Nettle 48 

Plantain,  Buckhorn,  Composite,  Bull  Thistle 49 

Canada  Thistle,  Cockle  Bur,  Ragweed 50 

Burdock    51 

Suggestions   for  the  Teacher 52 

Questions   and   Topics 53 

Bibliography    55 


A  STUDY  OF  WEEDS  IMPORTANT 


I  am  invited  to  address  you  this  afternoon  on  the  subject  of 
weeds.  I  am  sure  you  will  agree  with  me  that  this  is  a  most 
important  subject  for  the  farmers  of  Iowa  and  those  who  are  in- 
terested in  making  our  state  beautiful.  The  weeds  in  villages, 
cities,  along  the  highways  and  on  our  farms  are  a  continual  men- 
ace to  the  agriculture  of  this  state.  It  is  important  that  we  be- 
gin to  realize  the  menace  that  weeds  are  to  our  agriculture.  Iowa 
should  realize  the  importance  of  this  problem  and  we  should  be- 
gin at  once  to  clean  up,  because  it  is  far  more  economical  to  do 
so  now  than  in  a  decade. 

WHAT  IS  A  WEED. 

A  weed  has  been  defined  as  a  plant  out  of  place.  This  defini- 
tion is  concise,  but  is  as  good  as  any.  Oats  growing  in  a  wheat 
field,  if  not  wanted  there,  must  be  looked  upon  as  a  weed.  A 
weed  may  also  be  defined  as  a  plant  detrimental  to  the  growth 
of  a  garden  or  farm  crop,  in  short  detrimental  to  horticulture 
and  agriculture.  A  great  many  people  regard  plants  which  have 
inconspicuous  'flowers  as  weeds;  they  exclude,  of  course,  such 
plants  as  are  cultivated  for  some  purpose.  Such  people  regard 
the  inconspicuous  plants  of  the  forest  as  weeds,  forgetting  that 
plants  like  the  Dutchman's  Breeches,  Bloodroot  and  Hepatica 
are  most  useful  plants  in  the  forest  and  are  just  as  much  a 
part  of  it  as  the  oak  or  maple.  They  do  not,  however,  regard 
blu'  £rass  as  a  weed.  In  the  forest,  however,  bluegrass  must  be 
reg  /rded  as  a  weed.  In  a  bluegrass  pasture  such  plants  as  f  ox- 
tai/,  golden  rod,  vervain  and  crabgrass  are  weeds.  They  check 
the  growth  of  this  useful  forage  plant. 

KIND  OF  WEEDS. 

Weeds  may  be  classified  according  to  their  duration  of  life 
into  the  following  classes;  annual,  winter  annual,  biennial  and 
perennial. 

Annual. — The  annual  weeds  are  the  most  numerous  and  are 
easily  recognized.  The  seed  germinates  in  the  spring,  it  sends 
up  a  stem  which  produces  flowers  and  seeds  the  same  season  and 
then  dies.  Foxtail,  ragweed  or  kinghead,  smartweed,  crabgrass, 
horseweed  belong  to  this  class.  A  large  number  of  our  weeds 
belong  to  this  class. 

Winter  Annual. — These  weeds  do  not  differ  essentially  from 


the  annual.  The  seed  germinates  in  the  fall,  a  mat  of  leaves  is 
produced  and  the  next  spring  a  stalk  is  sent  up  which  produces 
flowers  and  seed,  then  dies.  Shepherd's  purse,  wild  barley  or 
squirrel  tail,  pepper  grass  in  our  climate,  but  in  the  south 
many  more  weeds  belong  to  this  class.  Winter  wheat  and  win- 
ter rye  are  winter  annuals. 

Biennial. — The  seeds  of  biennial  weeds  germinate  in  the  spring, 
the  plant  produces  a  mat  of  leaves  with  a  short  stem,  it  passes 
through  the  winter  in  this  way,  the  next  season  it  sends  up  a 
stem  on  which  flowers  and  seed  are  produced.  This  ends  its 
existence.  Burdock,  Parsnip,  Carrot,  Mullein,  and  Bull  Thistle 
are  representatives  of  this  type.  These  weeds  are  common  every- 
where in  the  ?tate. 

Perennial. — Ti^  nerennial  weeds  are  often  long  lived.  The 
seed  germinates,  somtL'mes  a  stalk  with  flowers  is  produced  the 
same  season.  The  ^lant  continues  to  live  year  after  year.  Peren- 
nial weeds  are  thv  most  difficult  to  exterminate.  Weeds  of  this 
type  are  numerous  and  in  Iowa  are  represented  by  Canada 
thistle,  Morning  glory,  Milkweed,  Quack  grass,  Nimble  will. 

HOW   WEEDS  SPREAD. 

Weeds  spread  in  two  days  by  (1)  vegetative  propagation  and 
(2)  seed  production.  Some  weeds  have  both  methods,  some 
only  one. 

Vegetative  Propagation. — In  this  method  of  reproduction  the 
stem  or  root  serves  to  propagate  the  plant.  This  is  brought 
about  in  three  ways,  (a)  by  stem  above  ground  or  under- 


Tumbleweed    (Amaranthus   graecizans) .      Scattered   by   the  wind  against 
fence.      (  Bergen. ) 


ground.  The  stem  may  be  recognized  through  the  presence  of 
leaves  or  scales.  Quack  grass,  Germander,  Northern  nut  grass, 
and  Morning  glory  spread  by  stems.  The  Quack  grass  stems, 
called  roots  commonly  are  near  the  surface  of  the  soil,  some- 
times over  three  feet  long,  and  every  severed  part  gives  rise 
to  a  new  plant,  (b)  These  plants  spread  by  roots,  sometimes 
they  are  flehsy  and  in  other  cases  they  are  thin  and  slender. 
Dock,  Horseradish,  Horse  nettle,  Sheep  sorrel  and  Dandelion.  The 
Milkweed  spreads  horizontally  in  the  soil  and  may  attain  a  length 
of  14  feet.  The  roots  of  the  Horse  nettle  on  the  other  hand 
spread  deeply  in  the  soil,  sometimes  to  a  depth  of  three  and  one- 
half  feet.  These  roots,  when  severed  give  rise  to  new  plants, 
buds  forming  on  these  roots,  (c)  The  third  type  propagates 
partly  by  root  and  partly  by  stem.  The  upper  part  of  the 
Canada  thistle  is  stem,  bearing  minute  scales  (leaves),  the  lower 

root  which  develops  buds. 

Seed  Propagation. — The  vast  majority  of  weeds  produce  seeds. 
The  only  weed  in  the  state  which  has  never  been  known  to  pro- 
duce seed  is  the  Horse  Radish.  It  flowers  frequently  but  seeds 
are  never  produced.  The  Canada  thistle  blossoms  freely  but  it 
does  not  seed  abundantly.  At  least  this  is  true  for  Iowa.  It 
relies  chiefly,  therefore,  on  vegetative  reproduction.  The  quack 
grass  spreads  as  freely  by  seeds  as  by  its  underground  stems. 
Some  weeds  produce  an  enormous  number  of  seeds,  from  a 
few  thouand  to  over  a  hundred  thousand  on  a  single  plant.  A 
single  seed  of  Squirrel  tail  grass  germinates,  from  this  seed  a 
large  number  of  stems  arise,  each  with  a  spike  that  contains  50 
or  60  seeds,  so  that  the  progeny  soon  becomes  greatly  multi- 
plied. 

Dr.  Beal  estimates  that  a  large  purslane  plant  produces  1,250,- 
000  seeds,  a  patch  of  daisy  fleabane  3,000  to  the  square  inch. 
We  found  the  following  number  of  seeds  per  plant,  horseweed 
324,000;  pigweed,  115,600;  Jimson  weed,  89,100.  Dr.  Halsted 
found  seeds  in  some  weeds  as  follows:  Speedwell,  186,292; 
Shepherd's  purse,  17,600;  Pepper  grass,  12,225;  Charlock,  9,900. 
Hitchcock  and  Clothier  record  the  weeds  seeds  as  follows :  Yellow 
foxtail,  113,600;  stink  grass,  180,000;  cocklebur,  9,700. 

DISSEMINATION   OR   SCATTERING    OF   PLANTS. 

The  scattering  of  plants  is  called  dissemination  and  this  is 
accomplished  in  the  following  ways:  (a)  wind;  (b)  water;  (c) 
animals;  (d)  explosive  properties;  (e)  seeds  burying  them- 
selves; (f)  man  as  an  agent. 

Wind. — The  wind  is  an  important  agent  in  a  large  number 
of  weeds.  The  dandelion  may  serve  as  an  illustration.  The 
"seed"  is  cylindrical  with  a  long  beak,  coming  from  the  beak 


7. 

are  a  large  number  of  fine  threads,  collectively  called  the  pap- 
pus. These  give  it  a  parachute-like  arrangement  and  permit  the 
seed  to  sail  through  the  air.  This  weed  owes  its  wide  distribu- 
tion to  the  facilities  for  dissemination.  Canada  thistle,  Bull 
thistle,  Horsewced  and  many  plants  of  the  Sunflower  family  have 
similar  contrivances.  The  Tumbleweed  is  another  type  of  weed 


a — Seed  of  beggar-tick's,  ft — Spanish  needle  carried  by  animals.  (C.  M. 
King.) 

Seeds  carried  by  the  wind:    a — golden  rod,  6 — blue  lettuce.     (C.  M.  King.) 

disseminated  by  the  wind.  The  plant  grows  in  circular  form  and 
when  mature  is  severed  from  the  root  close  to  the  ground.  In 
this  form  it  rolls  over  and  over  scattering  the  seed.  The  Rus- 
sian thistle  is  like  it,  but  each  seed  is  attached  by  a  slender  thread 
like  body  which  becomes  severed  from  the  plant,  drops  the  seed 
as  it  rolls  over  the  ground. 

Water. — Weeds  are  scattered  by  the  water  in  two  ways  (a) 
in  a  mechanical  way,  the  seeds,  plants  or  roots  are  carried  by 
the  water.  I  have  seen  fields  covered  with  wild  oats  that  had 
come  from  higher  ground  along  the  streams  or  ridges,  stems  of 
Quack  grass  have  been  scattered  by  the  water  in  this  way.  (b) 
Many  seeds  have  bladders  filled  with  air,  as  in  Dock.  The 
three  cornered  seed  is  surrounded  by  the  calyx;  one  or  more  of 
the  lobes  contain  a  cylindrical  body  called  the  tubercle,  this  is 
filled  with  air  and  makes  the  seed  boyant  which  enables  it  to 
float  down  the  stream  and  scatter  the  seed  wherever  it  is  lodged. 
The  seeds  of  Peppergrass  when  moistened  become  mucilaginous 
and  cling  to  the  hoofs  of  animals  or  shoes  and  in  this  way  steal 
a  ride. 

Animals. — Various  animals  like  cattle,  sheep,  horses,  squirrels, 


8. t , __ 

birds,  etc.,  scatter  seeds  and  fruits.  This  is  done  in  two  ways: 
(a)  Where  the  fruit  or  seed  is  edible  as  in  the  black  night  shade, 
cherry,  poison  ivy,  seed  of  dandelion,  thistle,  etc.,  crows  scatter 
large  numbers  of  seeds  of  the  poison  ivy.  Millions  of  these 
poison  ivy  seeds  are  annually  consumed  by  birds.  Large  num- 
bers of  seeds  of  the  dandelion,  thistle,  foxtail  are  consumed  by 
birds  some  of  these  are  accidentally  scattered  in  this  way.  Birds 
are  undoubtedly  useful,  however,  in  destroying  large  numbers 
of  weed  seed.  The  colored  fruits  usually  have  hard  seeds  so 
that  they  can  pass  the  digestive  tract  of  birds  uninjured,  (b) 
In  the  second  type  the  seeds  cling  to  animals.  Many  of  our 
weeds  have  excellent  contrivances  for  such  dissemination.  We 
will  mention  in  this  connection  the  cocklebur.  Each  cocKlebur 
has  two  so-called  seeds.  The  bur  is  provided  with  hooks  tna« 
cling  to  any  passing  animal  and  I  have  seen  them  scattered  for 
miles.  The  Burdock,  another  plant  of  the  same  family,  has  num- 
erous seeds  in  a  head;  the  hooked  appendages  get  in  the  hair, 
tails  of  horses,  cattle,  etc.,  where  they  form  balls  and  thus  the 
seed  is  scattered.  The  Spanish  needle  or  boot  jack  of  the  same 
family  has  a  flattened  seed  with  two  slender  pointed  bodies  that 
are  barbed  downwardly  like  grappling  irons ;  these  cling  to  pass- 
ing animals  and  carry  the  seed.  Another  weed,  the  Tick  Trefoil, 
belonging  to  the  Pea  family  has  a  pod  containing  several  seeds, 
this  pod  breaks  up  into  separate  pieces  when  ripe,  each  contain- 
ing a  single  seed.  The  pod  is  provided  with  hairs  that  are  hooked 
and  so  clings  to  animals.  When  removed  the  seed  has  often  trav- 
eled a  long  distance  with  the  animal.  Many  other  seeds  of  this 
family  like  Licorice  may  be  mentioned.  Weeds  with  similar 
contrivances  are  found  in  members  of  the  Borage  family,  like 
Hound's  tongue,  stickseed,  etc. 

Explosive  Properties. — The  seeds  of  a  few  weeds  have  explo- 
sive properties.  The  seeds  of  the  common  yellow  field  sorrel  has 
a  straight  pod  which,  when  mature  and  touched,  shoots  out  the 
seed  like  shot  from  a  gun.  The  pods  of  certain  vetches  contract 
and  twist  when  mature,  forcing  the  seed  out.  Contraction  of 
capsule  of  the  three-seeded  mercury  scatters  the  seed,  throwing 
it  some  distance.  This  method  of  scattering  can  be  observed  bet- 
ter on  such  a  plant  as  the  common  Castor  oil  bean. 

Seeds  Burying  Themselves. — A  few  of  our  weeds  bury  their 
seed,  but  the  needle  grass  growing  on  our  dry  sterile  hills  has 
a  sharp  point  to  its  "fruit,"  with  small  hairs  which  point  obli- 
quely upward.  There  is  also  a  long  awn  to  the  fruit,  this  is  sen- 
sitive to  moisture,  it  contracts  when  dry  and  straightens  out 
v  hen  moist  and  in  this  way  buries  the  seed. 


MAN  AS  AN  AGENT. 

Man  is  an  agent  in  many  different  ways  of  which  the  follow- 
ing may  serve  as  illustrations:  (a)  impure  seeds;  (b)  railways; 
(c)  vehicles;  (d)  threshing  machines ;  (e)  cultivation;  (f)  pack- 
ing materials;  (g)  wool;  (h)  plants  cultivated  for  ornamental 
purposes;  (ij  cultivated  for  food. 

Impure  Seeds. — Many  weed  seeds  are  scattered  with  various 
agricultural  and  garden  seeds.  Buckhorn,  dodder,  wild  carrot, 
ragweed,  nimble  will,  bracted  plantain,  dock,  quack  grass,  chic- 
ory, Canada  thistle  and  many  other  weeds  have  been  scattered 


Some  of  the  impurities  found  in  alfalfa :  la — alfalfa  seed,  Ib — toothed 
bur-clover,  Jc — spotted  bur-clover,  2c — yellow  trefoil,  2b — seed  natural  size, 
Sd — pod,  Sa — sweet  clover,  36 — seed  natural  size,  Jc — bracted  plantain  (Plan- 
tago  aristata),  5 — buckhorn  (Plantago  lanceolata) ,  6 — sour  dock,  7 — Canada 
thistle,  8 — dodder,  9 — quack  grass,  10 — sheep  sorrel,  11 — wire  grass  or  Canada 
bluegrass  (Poa  compressa),  12 — bluegrass.  (Lettered  figures  after  Hillman.) 

with  Agricultural  seeds.    One  farmer  in  Iowa  sent  to  rne  twenty 
different  kinds  of  weeds  found  in  his  clover  meadow  which  were 


10. 

introduced  with  clover  seed.  In  some  cases  it  is  difficult  to 
separate  the  weed  seeds  from  clover  seed  as  dock,  buckhorn  and 
bracted  plantain.  In  other  cases  there  is  no  excuse  for  the  pres- 
ence of  these  weed  seeds.  One  can  nearly  always  tell  where  the 
seed  comes  from  because  of  the  presence  of  certain  weed  seeds. 

It  may  be  of  interest  to  give  a  few  statistics  on  the  weed  seeds 
commonly  found  in  some  of  our  agricultural  seeds. 


Kind  of  Seed 

Purity 

Vitality 

Iowa  Standard 
Purity       Vitality 

Alfalfa   

../...    91  1 

87.6 
87.8 
87. 
76.6 
84.1 
60. 

96. 
92. 

90. 
96. 
90. 

80. 

80. 

75. 

85. 
85. 

Red  Clover 

966 

Alsike  Clover 

98  6 

White  Clover  

98.9 

Timothy           

98  9 

Millet  

96. 

The  more  important  impurities  found  in  red  clover  vary  with 
the  season.  The  imported  seed  may  contain  Canada  thistle, 
dodder,  buckhorn,  evening  catchfly,  wild  carrot.  Iowa  grown 
clover  seed  usually  contains  none  of  the  above,  but  ragweed,  dock, 
smartweed,  plantain,  dropseed  grass,  foxtail  and  sheep  sorrel  are 
common.  Western  grown  alfalfa  may  contain  black  medick,  burr 
clover,  chicory.  The  seed  of  sheep  sorrel,  yellow  foxtail  and 
curled  dock  may  also  occur.  Baehellor's  button  seed  as  well  as 
that  of  evening  catchfly  indicates  European  grown  seed.  Tim- 
othy seed  generally  contains  peppergrass,  curled  dock,  common 
plaintain.  The  seed  of  oats  may  contain  quackgrass  and  mus- 
tard. Wheat  seed  contains  the  seed  of  vetch,  corncockle,  chess, 
cowherb  and  mustard. 

IOWA   PURE   SEED   LAW. 

Seed  Legislation. — The  Iowa  law  has  the  following  provisions 
in  regard  to  the  sale  of  seed: 

Sec.  9.  The  term,  agricultural  seeds,  as  used  in  this  act,  shall 
include  the  seeds  of  the  red  clover,  white  clover,  alsike  clover, 
alfalfa,  Kentucky  blue  grass,  timothy,  brome  grass,  orchard 
grass,  red  top,  meadow  fescue,  oat  grass,  rye  grass  and  other 
grasses  and  forage  plants,  flax,  rape  and  cereals. 

Section.  10.  No  person  shall  sell,  offer,  or  expose  for  sale  or 
distribution,  in  this  state,  for  the  purpose  of  seeding,  any  of 
the  agricultural  seeds  as  defined  in  Section  Nine  (9  of  this  act, 
unless  the  said  seeds  are  free  from  the  seeds  of  the  following 
weeds:  Wild  mustard  or  charlock  (Brassica  sinapistrum),  quack 
grass  (Agropyron  repens),  Canada  thistle  (Cnicus  arvensis), 
wild  oats  (Avena  fatua),  clover  and  alfalfa  dodder  (Cuscuta 


n. 

epithymum),  field  dodder  (Cuscuta  arvensis),  and  corn  cockle 
Lychnis  githago).  * 

Sec.  11.  The  seeds  of  the  following  weeds  shall  be  considered 
as  impurities  in  the  agricultural  seeds,  as  defined  in  Section  Nine 
(9)  of  this  act,  sold,  offered,  or  exposed  for  sale,  within  the 
state  for  the  purpose  of  seeding:  White  cockle  (Lychnis  ves 
pertina),  night  flowering  catchfly  (Silene  noctiflora),  curled  dock 
(Rumex  crispus),  smooth  dock  (Rumex  altissimus),  sheep  sor- 


Impurities  found  in  red  clover:  1 — bull  thistle.  2 — Canada  thistle.  3 — 
green  foxtail  (Setaria  viridis),  4 — common  plantain  (Plantago  Rugelii),  5 — 
pepper  grass  (also  found  in  timothy),  6 — chicory,  7 — pigeon  grass  (Setaria 
glauca),  8 — crabgrass  (Panicum  sanguinale),  9 — old  witch  grass,  10 — timothy. 
11 — wild  carrot,  12 — pigweed  (Amaranthus  rctroflexus ) ,  13 — smartweed  (Poly- 
gonum  Persicaria),  14 — lamb's  quarter,  15 — dropseed  grass  (Muhlenbergia). 
(Charlotte  M.  King.) 

*The  scientific  names  have  been  changed  since  this  law  was  enacted. 
The  botanical  names  now  recognized  are  as  follows: — Common  Mustard 
or  Charlock  (BRASSICA  ARVENSIS)  Canada  Thistle  (CIRSIUM  ARVENSE) 
Corn  Cockle  (AGROSTEMMA  GITHAGO)  The  weed  law  has  the  names 
now  generally  recognized. 


12. 

rel  ("Rumex  acetosella),  yellow  trefoil  (Medicago  lupulina),  burr 
clover  (Medicago  denticulata),  sweet  clover  (Melilotus  alba  and 
officinalis)  black  mustard  (Brassica  nigra),  plantain,  buckhorn 
(Plantago  lanceolata),  bracted  plantain  (Plantago  aristata), 
bindweed  (Convolvulus  sepium),  smooth  crab  grass  (Panicum 
glabrum),  common  chickweed  (Stellaria  media).  When  such 
impurities  or  any  of  them  are  present  in  quantity  exceeding  a 
total  of  two  per  cent  of  the  weight  of  said  agricultural  seeds,  the 
approximate  percentage  of  each  shall  be  plainly  indicated  in 
statement  specified  in  Section  One  (1)  of  this  act. 

It  will  be  seen  from  the  above  extracts  that  seed  cannot  be 
sold  that  contains  more  than  two  per  cent  (2%)  of  the  weeds 
specified  in  Section  Eleven.  An  amendment  was  made  to  Sec- 
tion Ten  stating  that  the  weeds  specified  therein  must  not  be 
present  in  quantities  of  more  than  one  in  ten  thousand,  and 
that  due  diligence  has  been  used  to  find  and  remove  said  seeds. 

The  Iowa  law  has  greatly  improved  the  quality  of  seed  sold  in 
the  state.  The  farmers  are  demanding  a  better  quality  of  seed. 
The  seed  merchants  will  supply  the  demand  but  the  seeds  can- 
not to  be  sold  for  the  same  price.  In  cleaning  there  is  consider- 
able loss  and  the  farmer  should  be  willing  to  pay  for  this.  It 
will  cost  more  to  remove  the  bad  weeds  than  the  additional 
price  paid  for  the  better  seed. 

SOME    WEED    SEEDS 

Characters  of  a  Few  Weed  Seeds. — The  seeds  of  Canada,  thistle 
are  about  1-8  of  an  inch  long,  lance  shaped  in  outline,  tapering 
towards  the  base,  the  upper  part  is  cup  shaped,  with  a  yellowish 
rim,  a  conspicuous  point  appearing  in  the  center.  The  Bull 
thistle  is  much  like  it,  but  larger.  The  seeds  of  dodder  vary 
from  1-16  to  1-24  of  an  inch  in  diameter,  somewhat  flattened 
and  egg-shaped ;  the  color  varies  from  yellowish  to  light  or  dark 
green,  rough  and  dull,  not  smooth  as  in  clover  and  alfalfa. 
There  are  two  forms  of  dodder,  the  field  dodder  with  large  seeds 
and  the  clover  dodder.  The  seeds  of  quack  grass  are  sometimes 
difficult  to  distinguish  from  some  related  species  and  should  be 
submitted  to  a  botanist.  Bull.  115  of  the  Iowa  Agricultural  Ex- 
periment Station  describes  them. 

The  seeds  of  Ribgrass  or  Buckhorn  are  about  1-10  of  an  inch 
long,  shiny,  smooth,  dark  brown,  the  back  is  convex,  the  rounded 
edges  folded  inwardly  forming  a.  rim.  The  long  longitudinal 
groove  of  the  inner  face  with  a  dark  colored  spot  in  middle.  The 
Bracted  plantain  is  a  smaller  seed  broader  and  light  brown  in 
color,  a  long  groove  in  the  center,  on  the  back  is  a  circle.  Two 
light  colored  circular  areas  in  groove  are  characteristic.  The 
seed  of  the  Common  plantain  is  black,  roughened,  flattened  with 


13. 

acute  edges;  they  are  rhomboidal  in  outline,  from  1-12  to  1-16 
of  an  inch  in  length.  The  seeds  of  the  Common  pigweed  are  egg- 
shaped  or  lens  shaped  when  viewed  from  the  rim  or  border ;  they 
are  about  1-24  of  an  inch  in  length,  smooth  and  shiny.  The 
seed  of  Goosefoot  or  Lamb's  quarter  occur  in  several  forms,  us- 
ually nearly  spherical  with  attached  parts  of  the  flower,  the 
calyx  showing  ribs.  They  are  dull  brown  in  color.  Others  with 
a  thin  membranceous  covering.  The  "seed"  is  about  1-20  of  an 
inch  in  diameter,  nearly  spherical,  edges  somewhat  rounded,  sur- 
face somewhat  uneven,  jot  black  in  color,  sometimes  brightly 
polished.  The  "seeds"  of  Chicory  are  characteristic  about  1-10 
of  an  inch  in  length,  marked  by  longitudinal  lines  and  cross 
lines.  The  apex  with  a  double  row  of  whitish  scales,  color  dull, 


Fig.  5 — Mixture  of  weed  seeds  commonly  found  in  low-grade  alsike  clover 
seed :  a,  alsike  clover ;  b,  white  clover ;  c,  red  clover ;  d,  yellow  trefoil ;  e, 
Canada  thistle  ;  f,  dock ;  g,  sorrel ;  h,  buckhorn  ;  i,  rat  tail  plantain  ;  fc,  lamb's- 
quarters;  I,  shepherd's-purse  ;  in,  mayweed;  n,  scentless  camomile;  o,  white 
campion;  p,  night-flowering  catch-fly;  q,  oxeye  daisy;  r,  small-fruited  false 
flax ;  s,  cinquefoil  ;  t,  two  kinds  of  peppergrass ;  u,  catnip ;  v,  timothy ;  x, 
chickweed ;  y,  Canada  bluegrass ;  z,  clover-dodder ;  I,  mouse  ear ;  2,  knot- 

frass  ;  8,  tumbling  amaranth  ;  -},  rough  amaranth  ;  5,  heal-all ;  6,  lady's  thumb  ;. 
Enlarged.)      (Hillman.  U.  S.  Dept.  Agr.) 

very  dark,  brown  to  straw  color.  The  seeds  of  Bachellor's  but- 
ton are  oblong  or  obovoid,  compressed  or  4-angled,  smooth  and 
shining  attached  obliquely  with  a  disk  on  top  and  an  elevated 
margin.  These  seeds  occur  in  alfalfa. 

The  seed  of  May  weed  sometimes  found  in  clover  is  about  1-16 
of  an  inch  in  length,  bristly  club-shaped,  the  base  wider  than 
apex,  prominently  ribbed  and  tubercled.  The  "seed"  of  Small 
Ragweed  is  1-16 — 1-12  of  an  inch  in  length,  top  shaped  with 
prominent  projecting  teeth,  sometimes  absent,  and  a  beak.  Color 
dull.  Often  the  outer  part  missing  and  then  the  dark  smooth 


H. 

seed  only  shows.  The  greater  ragweed  is  like  it  but  much  lar- 
ger. The  seeds  of  Evening  catchfly  are  kidney  shaped  about 
1-18  of  an  inch  in  length,  thickish  and  roughened,  dull  grayish 
brown.  This  seed  is  very  common  in  European  and  Eastern 
grown  clover  seed.  Several  related  forms  have  seed  like  it.  The 
Cow  herb  seed,  however,  is  larger  and  more  nearly  spherical  about 
1-12  of  an  inch  in  diameter.  Mature  seeds  jet  black,  imature 
reddish,  the  surface  is  slightly  roughened  with  minute  project- 
ing points.  Another  related  seed  is  Corn  cockle;  these  are  about 
1-10  of  an  inch  in  diameter,  somewhat  triangular  in  outline, 
very  rough;  color,  dull  jet  black.  These  seeds  commonly  occur 
in  wheat  screenings.  It  is  more  or  less  poisonous.  A  number  of 
seeds  in  the  mustard  family  are  common  among  them;  Field 
mustard,  Black  mustard,  the  seeds  of  these  are  spherical  about 
1-18  of  an  inch  in  diameter,  blackish,  surface  covered  with  a  net 
work  of  delicate  ridges.  The  seeds  have  a  sharp  taste.  The  seeds 
of  Penny  cress  are  somewhat  egg  shaped,  broad  in  the  middle, 
brown,  the  surface  has  characteristic,  12-14  curved  ridges,  color 
of  seed  reddish  brown.  The  seeds  of  pepper  grass  of  the  same 
family  are  small,  about  1-16  of  an  inch  in  length,  light  reddish 
yellow  to  brown,  elongated,  egg  shaped,  much  flattened,  the  sur- 
face is  finely  grooved,  becomes  mucilaginous  when  moistened. 
The  seeds  are  found  in  clover  and  in  Iowa  especially  in  timothy. 
The  "seeds"  of  Carrot  are  flattened,  thin,  about  1-8  of  an  inch 
in  length,  bearing  numerous  spines,  these  are  generally  broken 
off.  Color  of  "seed' is  whitish  or  yellowish.  The  seeds  of  Black 
medick  are  similar  to  alfalfa,  but  more  egg  shaped  than  kidney 
shaped,  they  are  reddish  or  greenish  with  a  smooth  dull  surface. 
The  pods  are  characteristic  oval  or  kidney  shaped,  spirally  coiled 
and  blackish. 

The  White  sweet  clover  seed  is  about  1-12  of  an  inch  long, 
somewhat  flattened,  resembling  red  clover  in  outline,  elliptical- 
oblong  in  outline,  surface  smooth  and  dull  yellowish  or  green- 
ish. The  pods  often  occur  in  commercial  seed,  oval  in  outline 
1-8  of  an  inch  long,  marked  with  prominent  veins,  and  beaked. 
The  seeds  of  Common  vetch  are  spherical  blackish  and  large. 
The  seeds  of  Cinquefoil  are  about  1-24  of  an  inch  in  length,  straw 
colored  with  characteristic  longitudinal  ridges. 

Railways. — The  railways  scatter  many  different  kinds  of  weeds. 
The  right  of  way  of  the  railway  is  usually  one  of  the  best  col- 
lecting grounds  for  the  botanist.  Such  weeds  as  sunflower,  Buf- 
falo bur,  Russian  thistle,  gum  weed,  spurge,  western  wheat  grass 
are  common  along  the  trunk  lines.  The  seeds  drop  from  passing 
trains. 

Vehicles. — It  has  often  been  observed  that  vehicles  of  various 


15. 

kinds  may  be  a  means  of  scattering  weed  seeds.  Small  weed 
seeds  may  cling  to  mud  of  wheels  and  be  carried  to  some  distance 
away  from  where  the  seed  was  produced. 

Threshing  Machines. — Many  farmers  in  northern  Iowa  where 
quack  grass  is  becoming  abundant  claim  that  the  seed  of  this 
weed,  mustard,  vetch,  etc.,  is  scattered  by  means  of  the  threshing 
machine.  I  have  in  some  instances  verified  this  claim. 

Cultivation. — The  "roots"  of  various  weeds  are  easily  scat- 
tered by  the  cultivator.  A  small  patch  of  quack  grass  in  the 
corn  field  may  be  the  means  of  widely  scattering  the  plant  over 
the  field. 

Packing  material. — Various  kinds  of  packing  material  such  as 
is  used  for  packing  crockery  has  been  the  source  of  the  intro- 
duction of  Canada  thistle,  Awned  Brome  grass,  etc.  I  have  traced 
the  origin  of  these  weeds  in  this  way. 

Wool. — The  seeds  of  many  weeds  cling  to  the  fleece  of  sheep 
and  where  the  wool  is  cleaned,  and  the  debris  thrown  away  these 
weeds  spring  up.  Common  teasel  which  is  used  to  card  wool  is 
usually  found  around  the  woolen  mill.  Burdock,  cocklebur,  sand 
bur,  and  hound's  tongue  are  commonly  scattered  in  this  way. 

PLANTS  CULTIVATED  FOR  ORNAMENTAL  PURPOSES. 

In  this  state  we  have  two  conspicuous  examples  of  weeds  which 
at  one  time  were  commonly  cultivated  for  ornamental  purposes 
which  have  become  troublesome  weeds,  namely,  the  toad  flax  and 
bouncing  betty.  Here  and  there  the  European  bindweed  has 
been  scattered  in  this  way.  These  have  become  troublesome  weeds, 
difficult  to  exterminate  because  of  their  perennial  character.  Live 
forever,  cypress  spurge,  purple  pigweed  and  Mexican  firweed  are 
other  illustrations  of  weeds  introduced  in  this  way. 

Plants  Cultiva-ted  for  Food. — We  have  only  a  few  weeds  that 
belong  to  this  class  in  Iowa,  but  in  some  parts  of  the  United 
States  they  are  more  numerous.  The  conspicuous  examples  are 
chicory,  wild  carrot,  vegetable  oyster  plant,  hemp  and  parsnip. 

THE  WEEDS  OF  THE  IOWA  WEED  LAW. 

The  Thirty-third  General  Assembly  passed  a  law  making  it 
the  duty  to  remove  certain  weeds  from  the  public  highway, 
lands  adjacent  thereto,  streets  of  cities  and  villages,  right  of 
way  of  railroads  and  public  lands. 

Destruction  of  Weeds. 
Thirty-third  General  Assembly  of  the  State  of  Iowa. 

Section  1.  Land  Owners  or  Tenants  to  Destroy  Weeds — 
When.  It  shall  be  the  duty  of  every  person,  firm  or  corpora- 
tion owning,  occupying  or  controlling  lands,  town  and  city  lots, 
land  used  as  right  of  way,  depot  grounds  or  for  other  purposes 
to  cut,  burn  or  otherwise  entirely  destroy  all  weeds  of  the  kinds 


16. __^__ 

mentioned  in  section  two  (2)  hereof  at  such  times  in  each  year 
and  in  such  manner  as  shall  prevent  the  said  weeds  from  bloom- 
ing or  coming  to  maturity. 

Section  2.  Noxious  Weeds.  The  following  weeds  are  here- 
by declared  to  be  noxious  weeds,  namely,  quack  grass  (Agropyron 
repens),  Canada  thistle  (Cirsium  arvense),  cocklebur  (Xanthium 
Canadense),  wrild  mustard  (Brassica  arvensis),  sour  or  curled 
dock  (Rumex  crispus),  smooth  dock  (Rumex  altissimus),  buck- 
horn  or  ribbed  plaintain  (Plantago  lanceolata),  wild  par- 
snip (Pastinacasativa),  horse  nettle  (Solanum  Carolinense),  and 
velvet  weed  or  button  weed  (Abutilon  theophrasti)  and  burdock 
(Arctium  lappa). 

Section  3.  Destruction  on  Highways — neglect  or  Refusal  to 
Destroy.  It  shall  be  the  duty  of  the  township  trustees  or  other 
officers  responsible  for  the  care  of  public  highways  in  each  town- 
ship or  county  in  this  state  to  destroy  or  cause  to  be  destroyed 
all  noxious  weeds  mentioned  in  section  two  (2)  hereof  or  un- 
necessary brush  on  the  highways  in  such  a  manner  as  to  effec- 
tually prevent  the  production  of  their  seeds  or  their  propaga- 
tion in  any  other  manner,  to  warn  out  labor  or  to  employ  labor 
for  this  purpose  in  the  same  manner  as  for  repairs  to  the  high- 
ways, and  for  neglect  or  failure  to  perform  this  work  they  shall 
be  subjected  to  the  penalties  in  this  act.  If  any  occupant  of 
lands  adjacent  to  the  public  highways  neglect  or  refuse  to  de- 
stroy the  noxious  weeds  upon  his  land,  or  shall  fail  to  prevent 
the  said  noxious  weeds  from  blooming  or  coming  to  maturity, 
when  such  weeds  are  likely  to  be  the  means  of  infesting  the  pub- 
lic highway,  or  upon  complaint  of  any  land  owner  to  the  town- 
ship trustees  that  his  lands  have  been  or  are  likely  to  be  infested 
by  weeds  from  the  lands  of  another  including  railway  right  of 
way,  the  trustees  shall  make  investigation  of  such  condition  or 
complaint  and  if  the  same  appears  to  be  well  founded  they  shall 
make  an  order  fixing  the  time  within  which  the  weeds  shall  be 
prevented  from  maturing  seed,  and  an  order  that  within  one 
year  such  noxious  weeds  shall  be  permanently  destroyed,  and 
prescribing  the  manner  of  their  destruction  and  shall  forthwith 
give  notice  to  the  occupant  of  the  lands  where  the  noxious  weeds 
exist,  and  if  he  shall  neglect  to  obey  such  order  within  the  time 
so  ordered  the  trustees  may  cause  such  noxious  weeds  to  be  pre- 
vented from  maturing  seeds  or  may  cause  such  noxious  weeds  to 
be  permanently  destroyed  and  the  cost  of  the  work  shall  be  re- 
covered from  the  owner  by  a  special  tax  to  be  certified  by  the 
township  clerk  in  the  same  manner  as  other  road  tax  not  paid. 

Section  4.  Road  Funds  May  Be  Expended.  The  destruction 
of  noxious  weeds  in  the  public  highway  and  other  public  places 


17. 

is  hereby  made  a  part  of  the  road  work  of  the  township  trus- 
tees and  the  county  supervisors  and  they  shall  have  authority  to 
expend  road  funds  for  the  destruction  of  weeds. 

Section  5.  Property  Tax.  The  law  as  it  appears  in  section 
fifteen  hundred  and  twenty-eight  (1528)  of  the  supplement  to 
the  code,  1907,  is  hereby  amended  as  follows,  namely:  By  in- 
serting after  the  comma  in  the  eighth  line  thereof  the  following 
words:  "and  for  the  destruction  of  noxious  weeds  in  public 


Russian  Thistle,  a — mature  plant;  b— seedling,  about  two  weeks  after 
germination,  natural  size ;  c — flower  hanging  from  the  axil  and  remaining 
suspended  by  minute  hairs  in  the  ordinary  inverted  position  of  a  rolling  plant 
enlarged  3  diameters ;  d — flower  viewed  from  above  and  in  front,  showing 
the  calyx  lobes  forming  a  cone-shaped  body,  and  the  large  membranaceous 
spreading  wings,  enlarged  3  diameters ;  e — seed,  with  flower  part  removed ; 
enlarged  5  diameters ;  f — embryo  removed  from  seed,  enlarged  7  diameters. 
(U.  S.  Dept.  of  Agr.,  Bull  No.  15.) 

highways  and  other  public  places,"  and  by  striking  out  the  word 
"four"  in  the  tenth  line  of  said  section  and  inserting  the  word 
"six"  in  lieu  thereof. 


18.    

Section  6.  School  of  Instruction.  Between  November  and 
the  succeeding  April  of  each  year  the  county  supervisors  shall 
call  a  meeting  of  the  township  trustees  and  the  road  supervisors 
of  the  county  to  consider  the  best  methods  of  weed  extermina- 
tion and  road  building,  secure  services  of  experts  to  give  in- 
struction in  road  building  and  weed  destruction.  For  such  at- 
iendance  the  same  compensation  shall  be  allowed  to  the 
trustees  and  road  supervisors  and  the  county  supervisors  as  is 
allowed  by  law  for  other  services,  to  be  paid  as  other  expenses. 
The  expenses  of  experts  herein  provided  for  may  be  paid  from 
the  county  road  fund. 

Section  7.  Cutting  of  Weeds  on  li  i^hways.  It  shall  be  the 
duty  of  the  township  trustees  and  other  officers  directly  respon- 
sible for  the  care  of  public  highways  to  cause  to  be  cut  near  the 


Lamb's  Quarter.  Goosefoot  (Chenopodium  album).  A  branch  with  den- 
tate leaves  and  inflorescence.  1 — flower  with  calyx,  2 — seed.  (U.  S.  Dept. 
Agr.) 

surface  all  weeds  on  the  public  highways  in  their  respective  dis- 
tricts at  such  times  and  in  such  manner  as  to  prevent  seeds  from 


19. 

nurturing. 

Section  8.  Penalty.  Any  person,  firm  or  corporation  violating 
any  of  the  provisions  of  this  act,  or  any  township  trustees,  in- 
spector or  other  officer  who  neglects  or  fails  to  perform  the  duties 
incumbent  on  him  under  the  provisions  of  this  act,  shall  be  guilty 
of  a  misdemeanor  and  shall  be  punished  by  a  fine  not  exceeding 
one  hundred  dollars  ($100.00). 

Section  9.  Repeal.  The  law  as  it  appears  in  sections  fifteen 
hundred  and  sixty-two  (1562),  fifteen  hundred  and  sixty-two-a 
(1562-a)  and  fifteen  hundred  and  sixty -three  (1563)  of  the  sup- 
plement to  the  code,  1907,  and  sections  fifteen  hundred  and  six- 
ty-four (1564)  and  fifteen  hundred  and  sixty-five  (1565)  of  the 
sode  are  hereby  repealed. 

Approved  April  21,  A.  D.,  1909. 

OTHER  WEEDS. 

This  list  does  not  include  by  any  means  all  of  the  injurious 
weeds,  but  some  of  the  worst.  In  some  parts  of  the  state  some 
weeds  are  more  injurious  than  others.  Quack  grass  is  more  im- 
portant in  northern  Iowa  than  in  southern.  The  horse  nettle 
is  most  troublesome  in  southern  Iowa ;  cocklebur  is  troublesome 
in  all  parts  of  the  state.  The  velvet  weed,  the  smooth  dock, 
curly  dock,  and  burdock  are  widely  distributed. 

TREATMENT  OP  WEEDS. 

Weeds  in  order  to  be  eradicated  need  various  treatment.  The 
annual  and  biennial  are  not  so  difficult  to  exterminate  as  the  per- 
ennial. The  first  and  most  important  consideration  is  clean  cul- 
tivation. In  nearly  every  case  this  will  destroy  the  annual  weeds. 
The  land  for  corn  should  be  plowed  in  the  fall.  The  good  farmer 
will  practice  rotation  of  crops.  If  he  uses  the  following  rota- 
tion :  oats,  clover  and  corn,  the  clover  field  can  be  plowed  under 
after  the  removal  of  the  crop.  The  land  will  be  reasonably  clean, 
because  the  cloevr  is  an  excellent  plant  to  keep  many  weeds  down, 
especially  if  the  growth  is  rank.  In  the  spring  the  field  should  be 
disced,  and  the  seedlings  of  many  young  plants  will  be  destroyed. 
The  corn  field  should  then  be  given  clean  cultivation. 

It  is  common  practice  in  Iowa  to  sow  oats  directly  on  the  corn 
stubble,  simply  discing.  This  is  bad  practice.  It  would  be  far 
better  if  the  corn  could  be  cut  and  the  stalks  used  for  fodder, 
the  field  plowed  in  the  fall  and  the  oats  sown  in  a  clean  field. 
Usually  the  corn  fields  are  so  weedy  in  Iowa  that  it  is  difficult 
to  get  a  clean  field  of  oats.  The  time  is  coming  when  the  Iowa 
farmer  will  cultivate  his  fields  more  thoroughly. 

Clover  can  be  sown  with  oats,  if  the  stand  is  even  the  ground 
will  be  pretty  well  covered  the  next  season.  In  Iowa  clover  is 
usually  treated  as  a  biennial.  This  allows  two  years  for  a  clover 


20. 

crop.  The  above  treatment  can  only  be  recommended  for  an- 
nuals. Many  of  the  seeds  of  weeds  will  germinate  but  some  will 
keep  their  vitality  for  some  years  as  sweet  clover  and  Indian 
mallow  or  butter  print.  The  seeds  of  both  weeds  are  known  to 
keep  their  vitality  for  more  than  half  a  century. 
Perennial  Weeds. — The  above  methods  will  only  partially  destroy 
the  perennial  weeds.  Quack  grass,  Canada  thistle,  and  weeds 
of  this  character  need  special  treatment.  If  the  leaves  of  these 
perennial  weeds  are  prevented  from  growing  the  weed  will  be 
killed  in  the  course  of  time,  they  will  starve  usually,  however,  in 
ordinary  methods  of  cultivation,  but  some  plants  are  not  noticed 
and  these  give  rise  to  new  plants.  Let  me  give  a  few  weeds  with 
specific  treatment. 


Quack  Grass  (Agropyron  repens).  Creeping  rootstocks  and  a  number  of 
stems  (culms),  a  spikelet  at  a.,  each  containing  a  number  of  flowers,  o — a 
spikelet  with  sterile  glumes  at  2  and  flowers  above. 


21. 

TREATMENT    FOR    A    PEW    SPECIAL   WEEDS. 

Quack  Grass. — This  is  the  most  difficult  weed  to  exterminate  in 
Iowa.  There  is  no  easy  method.  It  can  be  removed  by  giving 
the  field  a  shallow  plowing,  in  the  summer  follow  with  a  harrow, 
bringing  the  roots  to  the  surface  and  continue  discing  and  har- 
rowing until  most  of  the  "roots"  are  destroyed.  Late  summer 
and  fall  is  the  time  to  do  this.  The  next  season  this  may  be 
followed  with  a  crop  of  sorghum  sown  very  thickly.  This  will 
probably  remove  most  of  the  quack  grass,  but  not  all.  Hemp 
may  be  sown  in  place  of  sorghum.  Dewey  claims  that  several 
fields  where  quack  grass  was  abundant,  the  hemp  plant  has  ma- 
terially held  the  quack  grass  in  check.  The  pasture  method  has 
been  recommended  by  Prof.  Spillman  and  what  I  have  seen  in 
Iowa  would  lead  me  to  believe  that  it  is  an  excellent  method. 
The  field  containing  quack  grass  is  put  in  meadow  and  pastured 
for  two  or  three  years  in  this  way.  This  method  causes  the 
roots  to  come  to  the  surface.  They  spread  less  freely  in  the 
meadow  than  in  cultivated  ground.  The  soil  is  plowed  two  to 
three  inches  deep  in  the  summer,  then  harrowed  two  or  three 
times  to  bring  the  "roots"  to  the  surface;  these  may  then  be 
removed  from  the  soil  and  burned.  If  the  season  is  favorable,  that 
is  dry,  two  or  three  harrowings  will  accomplish  the  killing,  but  if 
wet  some  "roots"  will  keep  alive  and  it  may  be  necessary  to  plow, 
say  not  less  than  six  inches.  After  this  has  been  done  two  or  three 
times  the  land  will  be  nearly  free  from  quack  grass.  The  field 
should  be  watched  and  when  quack  grass  appears,  it  may  be  re- 
moved by  digging  up  and  hoeing.  Deep  plowing  will  also  destroy 
the  roots,  but  this  can  seldom  be  done  well  and  some  "roots" 
are  to  be  seen  near  the  surface  which  will  develop  new  plants. 
The  roots  of  quack  grass  are  shallow  rooted. 

The  Cover  Method. — The  cover  method  can  be  applied  when 
the  patch  is  a  small  one.  For  this  use  tarred  paper  overlapping 
the  edges.  Leave  the  paper  on  the  quack  grass  for  six  months. 
A  heavy  coating  of  straw,  six  inches  to  one  foot,  will  also  be 
serviceable,  this  brings  the  roots  to  the  surface  where  they  can  be 
raked  off  and  burned;  then  plow,  harrow  and  cultivate. 

Canada  Thistle  and  Horse  Nettle. — These  weeds  are  deep  rooted 
and  in  order  to  destroy  them  it  will  be  necessary  to  plow  the 
field,  follow  with  a  harrow  two  or  three  times  and  keep  the  field 
clean  for  the  rest  of  the  season.  The  work  should  be  done  in 
midsummer;  if  all  of  the  plants  cannot  be  reached  by  the  har- 
row it  may  be  necessary  to  cut  the  plant  off  with  a  hoe.  Sodium 
arsenite  and  iron  sulphate  may  also  be  used.  It  is  sometimes  ad- 
visable if  the  patch  of  thistle  occurs  in  a  field  to  get  it  in  pasture 
and  place  a  lot  of  salt  around  the  Canada  thistle.  Stock  will 


22. 

then  destroy  the  weed. 

Morning  Glory  and  Milk  Weed. — Morning  glory  and  milk  weed 
can  best  be  kept  down  by  thorough  and  continued  cultivation.  If 
a  field  is  badly  infested  with  morning  glory  it  is  best  to  get  it 
into  pasture,  allowing  hogs  and  sheep  to  pasture  closely.  The 
cultivation  method  according  Cox  used  in  some  places  is  as  fol- 
lows : 

"Several  methods  for  accomplishing  this  eradication  have  been 
successful.  Clean  cultivation  is  one  of  the  best  in  many  cases. 
It  is  essential  to  employ  such  implements  as  will  keep  down  the 


Wild  Morning  Glory  (Convolvulus  scpium).  Two  large  bracts  at  the  base 
of  each  flower.  A  common  troublesome  weed  In  fields,  meadows  and  waste 
places.  (U.  S.  Dept.  Agr.) 

top  growth  successfully.    Where  the  weed  occurs  in  patches  these 
should  be  marked  oft'  arid  given  special  attention. 

"The  bindweed  may  be  greatly  reduced  or  entirely  destroyed 


23. 


by  seeding  the  land  to  alfalfa.  The  frequent  cutting  and  the 
shading  effect  of  this  crop  are  the  determining  factors.  Alfalfa 
should  be  followed  by  a  cultivated  crop  to  complete  the  work  of 
destruction. 

"Pasturing  with  hogs  has  been  successful  in  killing  bindweed, 
since  hogs  are  quite  fond  of  the  underground  parts.  This  me- 
thod can  be  used  with  both  ordinary  pasture  and  fallow  land. 
Results  can  probably  be  obtained  in  less  time  in  the  latter  case." 

Indian  Mallow. — This  weed  is  an  annual.  It  is  not  difficult  to 
exterminate,  cultivation  will  destroy  it.  The  great  difficulty 
with  this  weed  and  the  Shoo  fly  is  that  the  seeds  retain  their 
vitality  for  many  years.  There  are  cases  on  record  where  a  per- 
centage of  the  seeds  of  Indian  mallow  germinated  after  the  lapse 


Greater  Ragweed  or  King  Head  (Ambrosia  triflda).  Sometimes  called 
Horseweed.  Upper  p:irt  of  a  branch,  staminate  flowers  above,  pistillate 
flowers  just  above  the  leaves,  n — a  so-called  seed  more  properly  an  Involucre 


with   a   bract  on  the   right  hand 
Agr.) 


Ida, 


-with   bracts   removed.     U.    S.    Dept. 


24. 

of  half  a  century.  No  matter  how  much  cultivation  you  give 
the  soil  a  new  crop  of  weeds  will  appear. 

Sweet  Clover. — This  biennial  weed  is  common  in  many  parts  of 
the  state.  It  produces  a  tap  root  which  is  not  difficult  to  exter- 
minate by  cultivation.  As  in  the  preceding  case  the  seeds  retain 
their  vitality  a  long  time. 

Greater  Ragweed  or  Kinghxad. — This  weed  is  a  troublesome 
pest  in  many  Iowa  fields  along  fences  and  railroads.  The  plants 
are  easily  destroyed  in  fields  by  cultivation.  The  seed  probably 
retains  its  vitality  for  some  time.  Iron  sulphate,  100  pounds 
to  a  barrel  of  water  will  destroy  it.  Plant  clean  seed. 

Nimble  Will  or  Drop-Seed  Grass. — This  station  has  received 
many  letters  complaining  about  this  weed.  The  character  of  the 
"roots"  is  so  different  from  that  of  the  roots  of  quack  grass  and 
the  other  perennial  weeds  that  we  have  mentioned  before  that  it 
is  not  difficult  to  exterminate.  The  roots  of  this  weed  and  the 
allied  species  are  more  or  less  clustered.  In  an  experiment  con- 
ducted to  exterminate  this  weed  we  found  that  by  giving  a 
shallow  plowing  of  four  or  five  inches  and  harrowing  to  expose 
the  roots  to  the  sun,  they  were  killed,  no  growth  making  its  ap- 
pearance during  the  rest  of  the  season.  Of  course  this  is  not 
effective  during  rainy  weather. 

Cocklebur. — The  cocklebur  is  a  serious  menace  to  cultivated 
crops  in  many  parts  of  the  state,  more  especially  in  southern 
Iowa.  The  best  method  of  combating  the  cocklebur  is  the  rota- 
tion of  crops  and  clean  culture.  When  a  field  is  in  corn,  the 
field  should  be  thoroughly  cultivated  and  none  of  the  plants  al- 
lowed to  mature  seed.  If  they  cannot  be  caught  by  the  cultiva- 
tor, it  may  pay  to  kill  the  remaining  plants  with  a  hoe,  or  to  pull 
them  by  hand.  The  corn  should  be  followed  with  winter  rye  and 
then  oats,  using  the  oats  as  a  nurse  crop  for  clover  and  timothy. 
Leave  the  field  in  meadow  for  at  least  two  years  and  then  if  pos- 
sible turn  it  into  pasture.  This  certainly  eradicated  the  cockle- 
bur,  ragweed  and  many  other  annual  weeds. 

Summer  Fallow. — Undoubtedly  this  is  a  splendid  method  for 
the  eradication  of  weeds.  I  am  not  using  the  term,  however,  as 
it  is  ordinarily  used.  To  plow  and  then  leave  fallow  for  the 
summer,  but  constant  cultivation  and  harrowing  must  be  resorted 
to  in  order  to  remove  the  weed.  The  field  must  be  kept  free  from 
weeds  during  the  summer  and  fall. 

The  Use  of  Chemicals. — In  recent  years  many  experiments  have 
been  made  with  various  chemicals  to  destroy  weeds.  Among 
them  iron  sulphate,  sodium  arsenite,  corrosive  sublimate,  copper 
sulphate  and  common  salt. 

Some  of  these  substances  like  sodium  arsenite  and  corrosive 


25. 

sublimate  are  strong  poisons.  The  copper  sulphate  is  also  poison- 
ous but  less  so  than  the  other  solutions.  Sodium  arsenite  will  de- 
stroy Canada  thistle  and  many  other  weeds.  It  may  be  used 
at  the  rate  of  l1/^  pounds  to  52  gallons  of  water.  Stock  must 
be  kept  away  when  the  thistles  are  treated.  The  treatment  must 
be  repeated  as  often  as  thistles  appear.  Corrosive  sublimate  was 
found  to  be  efficient  in  killing  many  weeds,  but  is  not  to  be  recom- 
mended on  account  of  its  very  poisonous  nature.  Salt,  when  ap- 
plied in  sufficient  amount  is  efficacious,  but  it  is  expensive  when 
used  in  this  way  and  can  only  be  used  as  I  have  indicated  for 
Canada  thistle  and  Horse  nettle.  Iron  sulphate,  which  is  a  by- 
product in  the  manufacture  of  wire  is  cheap,  costing  in  100  pound 
bags,  92  cents  per  hundred  pounds  F.  O.  B.  from  several  Iowa 
points.  If  bought  in  200  pound  bags  it  costs  5  cents  less  per 
hundred  pounds.  It  comes  in  granulated  form,  is  readily  soluble 
in  water  and  may  be  made  in  various  strengths  of  solution.  For 
most  plants  it  is  used  at  the  rate  of  100  pounds  to  a  barrel  of 
water.  The  solution  cannot  stand  over  night.  It  may  be  applied 
with  a  hand  or  traction  sprayer.  I  have  found  it  efficacious  for 
the  following  plants:  Mustard,  ragweed  or  kinghead,  smart- 
weed,  dandelion,  artichoke,  velvet  weed,  small  ragweed,  lamb's 
quarter,  may  weed,  hedge  mustard,  pigweed,  boot  jack,  etc.  In 
fact  the  majority  of  weeds  found  in  grain  fields  readily  yield  to 
the  application  of  this  spray. 

WEEDS  OF  SPECIAL  CROPS. 

Small  Grain. — It  is  well  known  that  certain  weeds  occur  with 
certain  crops  since  the  very  earliest  times ;  such  weeds  as  common 
mustard,  darnel,  corncockle,  vetch  and  bindweed  or  wild  buck- 
wheat have  been  found  with  small  grain.  These  weeds  are  as 
common  in  Europe  as  in  the  United  States.  They  are  found 
wherever  small  grain  is  cultivated.  Formerly  it  was  difficult  to 
remove  these  weed  seeds  from  the  grain,  but  with  modern  me- 
thods of  screening  has  made  it  possible  to  remove  most  of  the 
weed  seeds. 

Corn. — Locality  sometimes  determines  the  kind  of  weeds  found 
in  the  field;  in  southern  Iowa  cocklebur,  horse  nettle,  arc  com- 
mon. In  northern  Iowa  quack  grass  and  artichoke  occurs.  The 
smartweeds,  fox  tail  pigeon  grass,  crab  grass,  shoestring,  milk- 
weed, pigweed  and  morning  glory  are  common  in  all  parts  of 
the  state.  In  early  spring  northern  nut  grass  may  appear; 
easily  recognized  by  the  yellowish  appearance  of  the  field.  The 
plant  has  grass-like  leaves  and  spreads  by  its  "roots."  Rag- 
weeds are  also  common  in  all  parts  of  the  state;  velvet  weed  is 
common  and  in  western  Iowa  marsh  elder  and  sunflower  are 
abundant. 


Garden  Weeds. — The  most  common  garden  weeds  are  purslane, 
pigweed,  lamb 's  quarter,  crab  grass,  nimble  will,  fox  tail,  spurge, 
boot  jack,  smartweed,  speedwell,  horse  weed,  etc.,  are  quite  uni- 
versal in  the  state. 

Meadows. — The  more  important  weeds  in  clover  meadows  are 
curled  and  smooth  dock,  fox  tail,  nimble  will,  horse  weed,  pep- 
per grass  and  smartweed,  yarrow,  pigeon  grass  and  small  rag- 
weed. The  buckhorn,  bracted  plantain,  chicory,  carrot,  white 
catchfly,  evening  catchfly,  black  medick  and  yellow  clover  are 
occasional  and  of  recent  introduction. 

Pastures. — In  Iowa  pastures  the  hoary  vervain  with  blue  flow- 
ers  in  long  spikes.  Small  ragweed,  pigeon  grass,  fox  tail  and 
golden  rod  are  the  most  conspicuous  weed  in  all  parts  of  the 
state. 

Roadsides. — The  weeds  of  the  roadside  are  generally  much  the 
same  as  those  occuring  in  adjacent  fields.  In  eastern  Iowa  dog 
fennel  or  may  weed,  yellow  clover  and  jimson  weed.  The  fol- 
lowing are  general  in  the  state:  Small  ragweed,  greater  rag- 
weed, horse  weed,  pitch  forks,  golden  rod,  morning  glory,  par- 
snip, milk  weed.  In  western  Iowa  marshelder,  sun  flower,  stink 
weed,  fetid  marigold  are  among  the  most  important  weeds. 

J'oisonons  Weeds. — The  laity  should  become  more  familiar 
with  the  poisonuos  plants  of  the  state.  There  are  a  great  many 
plants  which  are  more  or  less  poisonous  to  man  and  lower  ani- 
mals, a  few  are,  however,  deadly  poisonous.  Some  of  these  dead- 
ly poisonous  plants  are  found  in  all  parts  of  the  state.  The 
most  poisonous  of  these  is  the  cowbane  which  occurs  in  low 
grounds,  has  white  flowers  occurring  in  umbels,  leaves  divided, 
fleshy  roots,  clustered,  of  a  pungent  odor  and  taste.  The  roots 
are  deadly  poisonous,  a  small  amount  not  larger  than  a  hazel 
nut  taken  in  the  fall,  winter  or  spring  has  caused  death  to  a 
boy.  In  the  year  1909  near  Boone  two  boys  were  poisoned. 
One  lad  a  high  school  boy  picked  up  some  of  the  roots  which 
were  turned  over  by  a  farmer  while  breaking  a  meadow.  The 
boy  was  carried  to  a  farm  house  in  the  neighborhood  and  a 
call  sent  for  a  doctor.  The  doctor  made  a  rapid  trip  to  the 
house  in  his  automobile,  taking  the  boy,  but  when  the  hospital 
was  reached  he  died.  The  second  boy  died  under  somewhat  dif- 
ferent circumstances.  This  boy  later  evidently  picked  up  some 
of  the  plant  to  show  the  doctors  Avhat  his  companion  had  eaten 
and  later  he  developed  symptoms  resembling  those  found  in 
poison  ivy  poisoning.  Similar  cases  have  been  reported  else- 
where. Some  persons  who  pull  up  the  plant  get  eruptions  on  the 
skin.  I  am  told  that  the  same  thing  occurs  when  persons  pull 
or  come  in  contact  with  the  leaves  of  the  cultivated  parsnip 


27. 

riming  wild.  This  plant  has  yellow  flowers  and  a  straight  tap 
root.  The  root  so  far  as  I  know  is  not  poisonous  at  least  I  am  a 
witness  to  the  fact  that  the  root  of  the  wild  plant  is  not  poison- 
ous since  I  have  eaten  it.  Jimson  weed  is  another  poisonous 
plant.  The  plant  is  narcotic  and  has  a  pungent  odor.  It  has 
large  white  flowers  leaves  and  a  spiny  "pod"  (capsule)  with 
numerous  blackish  seeds.  These  seeds  are  very  poisonous.  Poison 
ivy  is  another  poisonous  plant  of  the  state  which  is  not  generally 
recognized  by  the  laity.  It  is  often  mistaken  for  Virginia 
creeper,  but  is  readily  distinguished  by  the  three  leaves — the  Vir- 
ginia creeper  having  five — the  leaves  of  the  poison  ivy  are  also 
wider.  The  poison  ivy  plant  may  grow  erect  or  creeping  over 
bushes  and  up  trees.  The  berries  are  white,  while  those  of  the 
Virginia  creeper  are  blue.  Poison  hemlock  is  another  poison- 


Cowbane  (Cicuta  maculata).  Common  in  low  ground;  flowers  white,  stem 
hollow,  fasciled,  fleshy  roots,  "seed"  fruit  to  the  right;  cross  section  lower 
left  hand  corner.  (U.  S.  Dept.  Agr.) 

ous  plant  in  the  state,  as  yet  not  common  it  belongs  to  the 
same  family  as  the  cowbane  and  parsnip.  The  plant  has  a  rank; 
smell  something  like  mice.  The  flowers  are  white,  small  in  urn- 


28. 

bels.  This  is  the  plant  that  Socrates  used  to  kill  himself.  Of 
the  other  poisonous  plants  I  may  mention  the  seed  of  castor  oil ; 
the  bark  of  black  locust,  the  flowering  spurge  with  milky  juice, 
the  cultivated  poppy,  mandrake  or  may  apple  sneezcweed  with 
yellow  flowers  found  in  marshes.  Wilting  sorghum  is  poisonous 
to  stock.  The  leaves  of  black  cherry  and  the  seeds  of  plum  and 
cherry  are  poisonous.  The  so-called  mushroom  should  be  avoided 
at  all  times,  especially  such  as  are  brilliantly  colored.  We  have 
several  deadly  poisonous  species  in  Iowa.  While  there  are  many 
edible  ones,  unless  you  are  familiar  with  them,  they  had  better 
be  left  alone. 

WHAT  TO  DO  IN  CASE  OF  POISONING. 

As  soon  as  possible  use  an  emetic  to  produce  vomiting,  use 
tartar  emetic;  salt  and  gruel  may  be  given,  follow  by  infusions 
of  hot  coffee  and  epson  salts.  In  case  of  poison  ivy  poisoning 
wash  with  soap  immediately  and  follow  with  acetate  of  lead. 


29. 


APPENDIX. 


Descriptions  of  a  Few  Weeds  Especially  of  the  Iowa  Weed  Law. 

GRASS  FAMILY —  ( Gramineae. ) 

We  have  a  large  number  of  weedy  plants  in  this  family.  In 
addition  to  those  mentioned  above,  atiention  may  be  called  to 
the  sandbur,  sprouting  crab  grass,  crowfoot  grass,  Johnson  grass, 
chess  or  cheat,  etc.  Mention  may  also  be  made  of  the  fact  that 
wheat,  rye,  barley,  oats  and  corn  belong  to  the  same  family. 


Foxtail  or  Piegon  Grass  (Setaria  glauca).  Annual  root,  a — sheath  and 
part  of  leaf,  b — a  spikelet  with  bristles  and  glumes  and  cross  striated  "seed". 
c-d-e-f — other  views  of  the  flower,  f  showing  stamens  and  stigmas  exserted ; 
pistil  and  stamens  enclosed  by  the  palea.  (Charlotte  .M.  King.) 

YELLOW  FOXTAIL — (Setaria  glauca  (L.)  Beauv.) 
An  erect  annual  one  to  two  and  one-half  feet  high,  flat  leaves 
bristly  cylindrical  spike,  from  one  to  three  inches  long.       The 
heads  are  slender  and  the  bristles  tawny  yellow.    The  small  seeds 


30. 

of  this  species  are  conspicuously  cross  striated  and  are  easily  dis- 
tinguished from  the  next  species  because  of  its  larger  size  and  by 
it  cross  striation.  This  species  also  comes  up  in  grain  fields  after 
harvest,  hence  seeding  the  soil  abundantly. 

GREEN  FOXTAIL — (Sctario,  mridis  (L)  Beauv.) 
An  erect  annual  from  one  to  three  feet  high,  leaves  four  to 
twelve  inches  long  with  rough  margins,  greenish,  more  or  less 
compound  cylindrical  spikes  from  one  to  five  inches  long  or  even 
in  some  cases  six.  Bristles  few,  much  longer  than  the  spikelets. 
Spikelets  one-twelfth  of  an  inch  long,  the  chaff  (second  and  third 
glumes)  as  long  as  the  minute  chaff  (fourth  glume),  the  latter 
being  dotted  and  striate.  A  single  head  produces  an  enormous 
number  of  seeds.  "When  fields  are  sown  to  oats  this  plant  comes 
up  in  the  fall  and  late  summer  Deeding  the  soil. 


Quack  grass  with  a  head  somewhat  more  enlarged.    (U.  S.  Dept.  Agr.) 

QUACK  GRASS — (Agropyron  repens  (L.)  Beauv.) 
A  perennial  with  widely  spreading  but  shallow  rootstocks  which 


31. 

form  dense  mats.  Flowering  stems  numerous,  smooth,  flowers 
in  spikes;  leaves  from  4  to  12  inches  long,  smooth  or  sometimes 
pubescent;  spike  3  to  10  inches  long;  the  separate  parts  of  the 
spikes  are  spoken  of  as  spikelets,  these  contain  from  4  to  8  flow- 
ers. The  chaffy  scales  of  the  spikelets  are  spoken  of  as  the  empty 
glumes.  Each  flower  has  a  flowering  glume  and  a  palet;  each 
flower  contains  stamens  and  pistils. 

This  plant,  quack  grass,  is  closely  related  to  western  wheat 
grass  which  may  be  readily  distinguished  by  the  glaucus  green 


Squirrel  Tall  Grass,  Wild  Barley  (Hordeum  jubatum).  Winter  annual 
or  annual,  a — part  of  stem,  b — portion  of  spike  showing  the  sterile  and  fertile 
flowers  and  the  long  awned  glumes,  c — single  flower  with  long  awned  glume. 
A  troublesome  weed  everywhere  in  the  state.  (Charlotte  M.  King.) 

Drop  Seed  Grass  or  Wild  Timothy  (Muhlenbergia  racemosa).  I  single 
spikelet  to  the  right.  Stalk  with  roots  (rootstock)  clustered. 

color  which  forms  a  decided  contrast  to  the  ordinary  green  of 
blue  grass  or  other  grasses  in  this  state.  The  spikelets,  too,  are 
denser  and  thicker.  This  grass  is  commonly  found  along  rail- 


32. 

ways.  Slender  wheat  grass  (Agropyron  tenerum)  has  slender 
spikes  from  4  to  8  inches  long;  the  numerous  rootstocks  are  ab- 
sent. Quack  grass  is  frequently  mistaken  for  drop  seed  grass 
(Muhlenbergia  mexicana)  but  this  may  be  readily  distinguished 
from  quack  grass  by  its  clustered  thick  and  short  rootstocks  and 
for  this  reason  sometimes  it  is  called  the  turkey  foot  grass.  The 
spikes  containing  the  seed  are  slender.  The  empty  glumes  are 
nearly  equal. 


Crab  grasses.    Left  hand  figure  common  Crab  grass  (PANICUM  SANGUINALE)  ;  right 
hand  figure  Smooth  Crab  grass  (PANICUM  GLABRUM). 

SQUIRRELTAIL  GRASS — (Hordeum  jubatum  L.) 
An  annual  or  winter  annual  from  six  inches  to  two  feet  high 
producing  fibrous  roots.  It  forms  solid  and  compact  bunches. 
Leaves  not  unlike  those  of  blue  grass,  but  paler  in  color,  from 
two  to  four  inches  in  length,  margins  scabrous.  Flowers  in  a 
dense  spike  from  two  to  four  inches  long,  pale  green  or  purplish 
in  color.  The  spike  consists  of  a  number  of  one-flowered  spike- 


33. 

lets,  three  occurring  at  each  joint,  only  one  is  perfect  (bearing 
stamens  and  pistil).  The  two  other  spikelets  are  awl-shaped 
and  rudimentary;  these  are  borne  on  short  stalks.  One  of  these 
sterile  spikelets  occurs  on  each  side  of  the  perfect  flower  which 
bears  a  long  awn.  At  each  joint  will  be  found  six  empty  long- 
awned  glumes  spreading  at  maturity.  These  give  to  the  plant 
the  bristly  appearance  at  maturity.  When  mature  the  spike 
breaks  up  into  joints  consisting  of  the  rudimentary  spikelets  and 
a  perfect  flower,  so  that  each  joint  has  one  "seed."  The  num- 
ber of  "seeds"  in  a  spike  varies  from  thirty-five  to  sixty.  A 
single  cluster  of  plants  may  therefore  produce  from  three  hun- 
dred to  two  thousand  mature  "seeds."  The  plant  has  a  won- 
derful capacity  for  "stooling. "  From  a  single  plant  as  many 
as  forty  spikes  may  be  produced,  and  the  number  no  doubt  often 
exceeds  this. 

CRAB  GRASS — (Panicum  sanguinale  L.} 

A  much  branched,  leafy  annual  one  to  three  feet  high,  spread- 
ing on  the  ground,  with  erect,  smooth,  spreading  culms,  frequent- 
ly rooting  at  the  lower  joints.  Joints  smooth,  though  more  fre- 
quently bearded  with  de'flexed  hairs.  Sheaths  loose,  generally 
pilose ;  hairy,  ciliate  on  the  margins,  with  a  membranaceous  ligule. 
Leaves  two  to  four  inches  long  with  rough  margins,  occasionally 
pilose  at  the  base.  Flowers  produced  in  digitate  spikes  hence  the 
common  name  finger  grass  is  sometimes  given  it.  Spikelets  less 
than  one-eighth  of  an  inch  long  in  pairs,  one  nearly  sessile  the 
other  with  a  stalk.  Each  flower  consisting  of  two  sterile  glumes 
(chaff)  and  the  flower  proper.  The  first  bract  very  small,  the 
second  about  one-half  to  two-thirds  as  long  as  the  spikelets,  us- 
ually hairy  on  the  margin.  The  third  glume  somewhat  longer 
than  the  fourth  which  is  five  nerved  and  usually  silky-villous 
along  the  marginal  nerves.  Fourth  glume  smooth  and  acute. 
The  fruit  is  minute,  pitted  and  cross  striated,  light  straw  color 
except  Avhere  the  sterile  glumes  remain  attached.  These  are  gray 
in  color  and  minutely  hairy. 

SEDGE  FAMILY — (Cyperaceae.) 

Of  the  Sedge  Family  the  most  important  weed  in  the  state  is 
the  northern  nut  grass  (Cyperus  esculentus)  ;  this  plant  is  read- 
ily recognized  by  the  yellowish  cast  of  the  corn  field  in  the 
spring  and  the  little  plant  has  corms  or  bulbs,  and  with  roots 
which  enables  it  to  spread. 

DOCK  AND  SMARTWEED  FAMILY — (Polygonaceae.) 

This  family  also  contains  a  large  number  of  important  weeds 
many  of  them  are  very  troublesome  to  our  crops.  Mention  may 
be  made  of  smartweed,  tanweed  or  devil's  shoestring,  sheep  sor- 
rel or  horse  sorrel,  all  common  weeds  in  this  state. 


34. 

CURLED  DOCK — (Eumcx  crispus  L.) 

This  weed  is  a  smooth  perennial  from  three  to  four  feet  high, 
leaves  with  strongly  wavy  and  curled  margins,  lanceolate  and 
acute.  In  the  lower  leaves  the  bases  somewhat  truncate  or  in- 
clined to  be  heart  shaped.  The  flowers  are  collected  in  dense 


Curled  Dock  (Ramex  crispus)   in  clover  meadows  and  along  roadsides.     A 
common  European  weed.      (U.  S.  Dept.  of  Agr.) 

whorls,  extended  or  prolonged  into  racemes,  entirely  leafless 
above,  but  below  with  small  leaves.  The  flower  consists  of  six 
sepals,  the  outer  herbaceous,  leaflike,  the  three  inner  larger  and 
somewhat  curled,  and  after  flowering  forming  the  valves  of  the 
fruit.  These  surround  the  three  angled  fruit  (achene)  all  the 
valves  bearing  a  grain. 


35. 

PEACH-LEAVED    DOCK   OR   PALE    DOCK — (RumCX    dltissimUS    Wood). 

A  tall  perennial  with  multiple  roots;  leaves  oval,  oblong,  lan- 
ceolate extending  into  a  point,  pale  and  thickish;  the  'flowers  in 
spike-like  racemes  or  panicles,  flowers  with  nodding  pedicels,  the 
valves  of  the  flower  are  obscurely  heart-shaped;  commonly  with 
a  conspicuous  inflated  grain.  Common  in  alluvial  soil  every- 
where in  the  state. 

SHEEP  SORREL — (Rumex  dcetoselld  L.) 

A  low  smooth  annual  or  perennial,  usually  the  latter,  growing 
from  six  to  twelve  inches  high ;  producing  an  erect  stem  ,with 
horizontal,  creeping,  woody  rootstock  or  rhizome ;  petioled,  nar- 


Sheep  sorrel  (RCMEX  ACETOSELLA)  . 
Dept.  Agr.) 


1  staminate  flower;  b.  pistillate  flower.    (U.  S. 


rowly  hastate,  narrow,  lanceolate  leaves,  the  upper  linear ;  flow- 
ers on  jointed  pedicels ;  dioecious  small  in  a  terminal  naked  pan- 
icle ;  small  green  calyx;  exserted  stamens;  the  valves  (inner  calyx 


36. 

lobe)  not  enlarging  in  fruit. 

GOOSEFOOT  FAMILY — (Ckenopodiaceae.) 

This  family  contains  a  number  of  common  and  troublesome 
weeds,  among  them  the  common  lamb's  quarter  or  goosefoot 
(Chenopodium  album),  a  weed  commonly  found  in  gardens  and 
along  roadsides.  Spinage  also  belongs  to  this  family. 

PIGWEED  FAMILY — (Amaranthaceae.) 

This  family  contains  a  number  of  troublesome  weeds,  in  this 
state  one  of  the  most  common  being  the  common  pigweed  (Amar- 
anthus  retroflexus) ,  and  the  common  Iowa  tumble  weed  (A. 
graecizans. ) 

PINK  FAMILY — (Caryophyllaceae.} 

Of  the  Aveeds  of  this  family  mention  may  be  made  of  the  cow 
Lerb,  common  in  grain  fields,  the  evening  catchfly,  wakerobin, 


Corn  Cockle  (Agrostemma  Githago).  A  hairy  plant  with  purple  flowers. 
The  long  outer  segments  are  lobes  pf  the  calyx,  2 — capsule  with  calyx  and 
seeds,  3 — kidney-shaped  seed.  (U.  S.  Dept.  Agr.) 


37. 

etc.    The  carnation  belongs  to  the  same  family. 

CORN  COCKLE — (Agrostemma  Githago  L.) 
A  hairy  annual  weed,  clothed  with  long,  soft  hairs.    Leaves 
linear-lancoolate,  acute  or  long  acuminate;  flowers  purple  and 
long  peduncled;  calyx  lobes  long,  linear,  surpassing  the  purple 
red  petals;  seeds  large,  roughened  and  black. 

ITKSLAXE  FAMILY — (Portiilacaccae.) 

This  family  contains  but  one  common  weed,  the  common  pusley 
or  purslane   (Portulaca  aleracea)   which  is  common  in  gardens 


Purslane  (P°rtulaca  oleracea).  General  view  of  plant  to  the  right.  1 — 
flower  in  cross  section,  pistil  in  center  with  ovules  attached,  stigmas  above, 
stamens  to  the  right  and  left,  2 — A  capsule  with  a  line  in  the  middle  where 
the  capsule  splits.  3 — The  same  with  top  of  capsule  removed  showing  the 
seeds.  4 — Seed.  5-6 — Stamens.  (U.  S.  Dept.  Agr.) 

everywhere  in  the  state,  and  the  common  moss  rose  of  Peru  is 
cultivated. 


38. 


Charlock  or  Mustard    (Brassica  arvensis).     A  common  weed  in  grainflelds 
ind  waste  places.      (U.   S.  Dept.  Agr.) 


CROWFOOT  FAMILY — (Ranunciilaceae. ) 

.V  number  of  weeds  are  members  of  this  family,  among  them 
the  common  crowfoot  with  a  sharp  acrid  taste  (Ranunculus 
abortivus]  ;  also  such  cultivated  ornamental  plants  as  the  peony, 
larkspur,  aconite,  columbine  and  clematis.  Many  of  these  plants 
are  poisonous.  . 

MUSTARD  FAMILY —  ( Cru tiferae. ) 
Among:  the  common  weeds  not  described  below  mention  may 


Butter  Print  or  Indian  Mallow  (Abutilon  theophrasti) .  A  velvety  pubes- 
cent annual,  flowers  ami  capsule ,  e  ach  division  with  several  seeds.  (U.  S. 
Dept.  Agr.) 

be  made  of  the  tumbling  mustard,  pepper  grass  (Lepidium 
apctalum),  common  everywhere  in  the  state.  Cabbage,  turnip 
and  rutabaga,  and  mustard  belong  to  the  same  family. 
MUSTARD  OF  ENGLISH  CHARLOCK — (Brassica  arvensis  (L.)  Ktze.) 
Lower  leaves  nearly  divided  to  the  middle,  with  the  divisions 
unequal,  the  terminal  lobe  larger.  Upper  leaves  sessile  much 


40. 

smaller  than  the  lower.  Flowers  yellow,  large  and  very  fragrant. 
Pods  one  to  two  inches  long,  irregular  in  outline,  appearing 
somewhat  nodose,  three  to  seven  seeded  or  more  occasionally. 
The  upper  part  of  pod  forms  the  beak.  Seeds  round,  brownish 
black,  darker  than  in  B.  nigra  and  minutely  pitted.  The  pods 
of  black  mustard  shorter  and  angled.  Seeds  of  all  of  the  mus- 
tards mucilaginous.  There  are  many  other  mustards  in  the  state 
like  hedge  mustard,  pepper  grass,  etc. 


Wild  Carrot  (Daucus  Carota).  Common  in  the  East  in  clover  meadows 
and  introduced  into  this  state  with  clover  seed.  A  bristly  hairy  biennial.  1 
— general  view,  2 — flower  with  stamens,  pistil,  corolla,  3 — fruit.  (U.  S.  Dept. 
Agr.) 

MALLOW  FAMILY — (Malvaceae.) 

A  number  of  very  common  weeds  in  this  state  belong  to  this 
family,  among  them  the  common  cheeses,  and  crisp  mallow,  also 
such  ornamental  plants  as  the  hollyhock. 


, 4L 

BUTTER  PRINT  OR  VELVET  WEED — (Abutilon  Theophrasti  Medic.) 
A  tall  annual  from  two  or  four  feet  high;  leaves  roundish 
heart-shaped  and  velvety,  pubescent,  taper  pointed,  pedicels 
shorter  than  the  leafstalk ;  flowers  small  with  yellow  corolla ;  pod 
consisting  of  12  to  15  beaked  carpels  which  are  pubescent.  Com- 
mon in  waste  places  and  vacant  lots.  Seeds  preserve  their  vital- 
ity for  a  long  time. 


Field  Dodder  (Cuscuta  arvensis).  Found  on  clover.  a — flower;  b — 
flower  spread  apart ;  c — capsule  with  stamens  and  styles  therein ;  d — seed. 
(Dewey  Division  of  Botany,  U.  S.  Dept.  Agr.) 

Alfalfa  Dodder  (Cuscuta  epithymum).  a — flower;  b — flower  spread  apart 
to  show  stamens  and  corolla ;  c — capsule  showing  styles ;  d — seed.  (U.  S. 
Dept.  Agr.) 

PARSELY  FAMILY — (Umlellifcrae.) 

This  family  contains  a  number  of  weeds  some  of  them  most 
troublesome.  In  addition  to  those  described  below  mention 
may  be  made  of  the  poison  hemlock  (Conium  maculatum},  some 
of  the  cultivated  plants  are  the  carrot,  parsley,  lovage  and  dill. 


42. 

This  family  contains  some  of  the  most  poisonous  plants  in  the 
vegetable  kingdom,  like  the  cowbane  or  water  hemlock  and  poison 
hemlock. 

PARSNIP — (Pastinaca  sativa  L.) 

A  biennial  with  grooved  stems;  pinnately  compound  leaves, 
with  ovate  to  oblong  cut  toothed  leaflets.  Fruit  oval  to  flattened 
with  broad  wings.  This  tall  stout  glabrous  or  somewhat  pubes- 
cent biennial  is  as  escape  from  cultivation.  It  has  a  straight  tap 
root  in  place  of  multiple  thick  fleshy  roots  as  the  poisonous  hem- 
lock or  cowbane  frequently  called  parsnip  in  this  state. 


Horse  Nettle  (Solanum  carolinense) ,  a  perennial  weed  troublesome  in 
southern  Iowa.  Potato-like  flowers  and  prickly  stem  (Division  of  Bot., 
U.  Dept.  Agr.) 

Buckhorn  (Plantago  lanceolata).  With  a  timothy-like  head  and  elongated 
leaves.  Common  in  clover  meadows.  (Charlotte  M.  King.) 

CARRROT — (Dau-cuK  Carota  L.) 
A  biennial  or  annual  with  bristly  stems  and  pinuately  decom- 


43. 

pound  leaves;  bracts  surrounding  the  flowers  leaf -like;  white 
flowers  in  umbels  becoming  concave.  This  plant  with  a  straight 
tap  root  has  been  widely  distributed  with  clover  and  alfalfa.  It 
is  one  of  the  most  pernicious  weeds  of  the  eastern  meadows. 


Bull  thistle  (Cirsium  lanceolatum).  A  troublesome  biennial  weed  common 
in  woods,  pastures  and  along  roadsides.  (U.  S.  Dept.  Agr.) 

COWBANE.      WATER  HEMLOCK — (ClCUta  maculatd  L.) 

It  is  a  smooth  marsh  perennial  two  to  five  feet  high  with  pin- 
nately  compound  leaves  two  or  three  times  pinnate;  the  leaves 
have  long  petioles,  the  coarsely  serrate  leaflets  are  lanceolate  to 
oblong  lanceolate  one-fifth  inch  long.  Stalks  of  the  umbellets 
numerous  and  unequal.  Flowers  white,  fruit  broadly  ovate  to 
oval,  small  one  and  one-half  inches  long.  Grows  in  marshes 
and  in  low  grounds.  The  stems  spring  from  thick  fleshy  under- 
ground roots  that  taper  at  the  lower  end.  These  usually  number 
from  three  to  five,  but  single  specimens  are  also  met  with.  On 


44. 

cutting  the  roots  a  sharp  pungent  odor  is  given  off. 

MORNING  GLORY  FAMILY — (ConVOlvuldCeae.) 

In  addition  to  the  weeds  described  below,  we  have  the  Euro 
pean  bindweed  or  morning  glory,  the  southern  morning  glory 
(Ipomoea  purpurea)  and  related  species.  The  sweet  potato  be- 
longs to  this  family. 


Canada  thistle  (.Cirsium  arvcnse).  A  common  troublesome  weed  in  gar- 
dens, roadsides  and  sometimes  in  clover  fields.  Notice  the  perennial  roots  at 
2,  and  the  flowers  at  3.  (U.  S.  Dept  Agr.) 

DODDER —  (  CllSCUttt   Spp. ) 

The  dodders  are  leafless  excepting  the  small  scales  on  the 
stems,  herbs  of  reddish  or  yellowish  color,  with  thread-like  stems 
twining  around  the  plants  upon  which  they  live.  They  pierce 
the  plant  with  small  and  short  rootlets  which  are  called  suckers 
or  haustoria.  The  seeds  are  small,  yet  there  is  stored  sufficient 
nourishment  in  them  to  give  the  embryo  a  start.  The  seed  ger- 


.45 

minates  in  the  soil  and  grows  sufficient  in  length  to  allow  it  to 
come  in  contact  with  the  plant  upon  which  it  lives,  when  it  im- 
mediately sends  in  its  suckers,  and  thus  becomes  established  upon 
the  plant  as  though  it  were  a  part  of  the  host. 

The  dodders  contain  no  chlorophyll,  the  green  coloring  matter 
iound  in  leaves,  and  hence  cannot  make  food,  that  is,  make  starch 
out  of  raw  material  such  as  ordinary  green  leaves  do,  but  must 
derive  nourishment  entirely  from  the  host  upon  which  they  live. 
Such  plants  are  called  parasitic. 


Cockle    Bur    (Xanthium    canadense.) 
(U.  S'.  Dept.  Agr.) 


Weed    of   cornfields    and    roadsides. 


We  have  two  troublesome  dodders  in  this  state,  the  clover  dod- 
der (Cuscuta  epithymum  Murr.)  on  alfalfa  and  clover,  with 
slender  stem  with  elongated  stigmas  and  field  dodder  (C.  arven- 
sis)  with  capitate  stigmas. 

HEDGE   BINDWEED   OB   MORNING   GLORY — (Convolvulus  septum   L.) 


47. 


NIGHTSHADE  FAMILY  —  (  Solanctceae.  ) 

This  family  contains  a  number  of  very  troublesome  and  per- 
nicious weeds,  among  them  the  common  black  nightshade  (Sola- 
num  nigrum]  with  small  white  flowers,  the  Buffalo  bur  (S.  ros- 
tratum)  with  prickly  stems  and  fruit  and  yellow  flowers,  leav.es 
resembling  those  of  the  water  melon;  the  ground  cherry  (Phy- 
salis),  the  Jimson  weed,  two  types,  both  species  poisonous.  Of 
the  cultivated  plants  it  contains  the  potato,  tomato  and  tobacco. 


Burdock    (Arctium 
gardens  and  pastures. 


Lappa).      A   common    biennial   weed 
(Divi 


waste   places, 


ision  of  Bot.,  U.  S.  Dept.  Agr.) 

HORSE  NETTLE  —  (Solanum  carolmense  L.) 
Horse  nettle  is  a  deep-rooting  perennial,  propagating  freely 
by  its  underground  roots,  these  running  roots  are  often  three 
feet  long;  stem  from  one  to  two  feet  high,  somewhat  straggling, 
half  shrubby  at  the  base  ;  stem  hairy  or  merely  roughish  with 
minute  hairs  which  are  star-shaped,  also  armed  with  stout  subu- 


46. 

Smooth,  occasionally,  however,  pubescent,  twining  around  sup- 
ports or  trailing.  Leaves  triangular,  halberd  or  arrow-shaped, 
the  tip  acute,  or  pointed,  the  basal  lobes  obliquely  truncate  or 
sinuate  lobed.  The  flowering  peduncles  four  angled  with  two 
leaf -like  bracts  which  are  commonly  acute.  Corolla  is  white  or 
tinged  with  rose  purple. 


Small  Ragweed  (.Ambrosia  artemisiaetolia) .  With  deeply  divided  leaves 
and  branches  with  flowers.  1 — head  with  staminate  flowers,  2 — pistillate 
flower  containing  the  "seed."  (U.  S.  Dept.  Agr.) 

MINT  FAMILY — (Labiatae.} 

A  number  of  troublesome  weeds  like  the  catnip,  common  ger- 
mander or  wood  sage,  and  peppermint,  with  creeping  " roots";  of 
the  cultivated  species  the  scarlet  sage,  peppermint,  hyssop,  etc. 
Many  of  the  plants  have  a  pungent  flavor,  and  square  stem,  and 
thus  are  easily  recognized. 


48. 

late  yellowish  prickles  which  are  usually  numerous ;  leaves  oblong 
or  sometimes  ovate,  obtusely  sinuate,  toothed  or  lobed  or  deeply 
cut,  two  or  four  inches  long.  The  flowers  are  borne  in  what  are 
called  racemes,  which  later  become  one-sided;  the  outer  part  of 
the  flowers,  the  calyx,  consist  of  slender  lobes,  the  corolla  is  light 
blue  or  white,  an  inch  or  less  in  diameter.  The  flowers  are  fol- 
lowed by  the  yellow  globose  berries,  half  to  three  quarters  of  an 
inch  in  diameter.  The  seeds  are  yellowish,  a  little  less  than  one- 
twelfth  of  an  inch  long,  minutely  roughened.  The  flowers  re- 
semble those  of  the  common  potato,  and  are  blue  or  white,  an 
inch  or  less  in  diameter.  The  yellow  berries  also  resemble  those 
of  the  potato.  The  spiny  character  of  the  leaves  and  the  further 
resemblance  of  the  flower  to  the  potato  should  render  it  easy  of 
detection. 

PLANTAIN  FAMILY —  ( Plant aginaceac. ) 

Of  the  plantains  the  most  common  weed  not  described  is  the 
common  dooryard  plantain  of  which  there  are  two  kinds,  Plan- 
logo  major  and  P.  Kugelii;  the  bracted  plantain  is  becoming  a 
troublesome  weed  in  the  southern  part  of  the  state,  especially  in 
clover  fields.  This  plant  is  something  like  the  common  plantain 
but  the  leaves  are  narower  and  the  heads  with  large  bracts. 
BUCKHORN — (Plaoitago  lanceolata  L.) 

A  perennial  or  biennial,  pubescent,  with  short  erect  root-stocks ; 
leaves  narrowly  oblong  lanceolata  ,somewhat  shorter  than  the 
scape,  three  to  five  ribbed ;  scapes  slender  with  spikes  dense,  at 
first  capitate,  later  becoming  cylindrical ;  bracts  and  sepals  scari- 
ious,  brownish;  calyx  of  four  persistent  sepals  and  glabrous  co- 
rolla. Two  small  smooth  brownish  seeds  found  in  each  vessel. 
COMPOSITE  FAMILY —  ( Compositae. ) 

The  Composite  or  Suriflower  Family  is  a  large  family  of  plants 
containing  some  of  the  most  troublesome  of  our  weeds.  The  fam- 
ily gets  its  name  from  the  common  sunflower  which  is  wreedy  in 
the  western  part  of  the  state,  but  in  addition  there  are  a  large 
number  of  other  weeds  of  this  family  like  the  dandelion,  May 
weed,  sneeze  weed,  marsh  elder,  troublesome  in  western  Iowa, 
the  leaf  looks  something  like  the  sunflower,  but  the  flowers  are 
like  the  common  ragweed,  tansy,  and  so  on.  Of  the  cultivated 
plants  attention  may  be  called  to  the  lettuce  and  chicory.  Sneeze 
weed  with  yellow  flowers  growing  in  low  ground  is  poisonous. 
Aster,  golden  rod,  horse  weed  and  dandelion  belong  to  this  fam- 
ily. 

BULL  THISTLE — (Cirsium  lanceolatum  Willd.} 

A  branching  biennial,  three  to  four  feet  high,  tomentose,  be- 
coming dark  green  and  villous  or  hirsute  with  age,  branchlets 
bearing  large  heads ;  leaves  lanceolate,  decurrent  on  the  stem  with 


49. 

prickly  wings  deeply  pinnatifid,  the  lobes  with  rigid  prickly 
points,  upper  face  roughened  with  short  hairs,  lower  face  with 
a  cottony  tementum ;  heads  one  and  three  quarters  to  two  inches 
high,  bracts  of  the  involucre  lanceolate,  rigid  when  young,  more 
flexible  with  age,  long  attenuated  prickly  pointed  spreading  tips, 
arachnoid  woolly;  flower  hermaphrodite,  tube  of  the  corolla  ten 
lies  long,  anther  tips  acute,  filaments  pubescent,  achenes  smooth, 
one  and  a  half  inches  long,  pappus  of  numerous  plumose  bristles. 
CANADA  THISTLE — (Cirsium  arvense  (L.)  Scop.) 

A  smooth  perennial,  spreading  by  creeping  roots  and  root- 
stocks,  one  to  three  feet  high,  corymbosely  branched  at  the  top ; 
stem  smooth;  leaves  lanceolate,  sessile,  and  deeply  pinnatifid, 
lobes  and  margins  of  leaf  with  spiny  teeth ;  heads  small,  three- 
fourths  to  an  inch  high,  bracts  appressed,  the  outer  with  a  broad 
base,  inner  narrow,  all  with  an  acute,  never  spiny  tip ;  flowers 
purple,  dioecious,  one  plant  with  stamens  and  the  other  with 
pistils.  Common  in  many  parts  of  the  state. 

COCKLE  BUR — (Xanthium  canadense  Mill.) 

A  course,  rough  annual  from  one  to  three  feet  high,  stem 
marked  with  brown  punctate  spots;  leaves  alternate,  cordate  or 
ovate,  three  nerved,  long  petioled.  Flowers  monoecious,  stamin- 
nate  and  pistillate  flowers  in  different  heads,  the  pistillate  clus- 
tered below.  The  involucre  of  the  staminate  flowers  somewhat 
flattish  of  separate  scales,  receptacles  cylindrical.  Scales  of  the 
fertile  involucre  closed  in  fruit  two  beaked,  containing  two 
achenes  (seeds).  The  bur  is  densely  prickly  and  hispid,  the 
achenes  are  oblong  without  pappus.  At  the  upper  end  of  the 
involucre  are  two  large  prickles. 

Each  bur,  as  stated  above,  contains  two  flowers  which  develop 
into  the  "seeds."  The  statement  is  frequently  made  "that  one 
of  these  may  germinate  the  first  year,  and  the  other  lie  dormant 
until  a  later  time.  It  has  been  found  that  if  a  bur  lies  in  such 
a  position  that  one  seed  is  up  and  other  down,  the  one  next  the 
soil  may  germinate  while  the  other  remains  dormant.  This  is 
one  reason  why  the  plant  is  difficult  to  exterminate. 

GIANT  RAGWEED.     KiNGHEAD — (Ambrosia  trifida  L.) 

This  weed  is  a  stout  scabrous,  hispid  or  nearly  glabrous  an- 
nual, three  to  twelve  feet  high.  Leaves  all  opposite  and  petioled 
three  nerved,  deeply  three  to  five  lobed,  the  lobes  are  ovate  and 
lanceolate  and  serrate,  the  upper  leaf  sometimes  ovate  and  undiv- 
ided; flowers  monoecious,  staminate  borne  in  spikes  surrounded 
by  the  larger  bract-like  leaves.  The  involucre  is  turbinate  to 
obovoid,  five  to  seven  ribbed,  beaked,  each  rib  bearing  a  tubercle 
near  the  summit;  the  involucre  enclosing  a  single  oily  seed, 


50. 

SMALL  RAGWEED — (Ambrosia  artemisiaefolia  L.) 
This  weed  is  a  puberulent  or  hirsute  annual,  branched,  one  to 
three  feet  high;  leaves  thin,  once  to  twice  pinnatifid;  the  upper 
leaves  are  alternate,  the  lower,  usually  opposite,  pale  or  canescent 
beneath.  Flowers  monoecious,  the  staminate  above  and  the  pis- 
tillate in  the  lower  axils  of  the  leaves.  The  fertile  heads  are 
obovoid  or  globose.  Short  beaked.  Four  to  six  spined. 

BURDOCK — (Arctium  Lappa  L.) 

A  coarse,  branched  biennial  from  a  foot  to  three  feet  high; 
hairy ;  leaves  large,  roundish  or  heart-shaped,  thin,  obtuse,  entire 
or  dentate,  floccose  tomentose  beneath.  Petioles  deeply  fur- 
rowed, heads  of  purplish  or  whitish  flowers,  clustered  or  some- 
what corymbose.  The  involucre  surrounding  the  flowers  (heads) 
are  lengthened  into  hooked  tips,  glabrous  or  slightly  cottony. 

Where  burdocks  are  allowed  to  grow  freely  the  fruit  clings 
to  the  fleece  of  animals,  often  forming  large  balls  which  may  be 
found  on  the  tails  of  cattle  and  horses.  When  they  are  common 
where  sheep  pasture  the  burdocks  work  into  the  wool  which 
soon  becomes  of  little  value.  The  plant  is  enormously  produc- 
tive. 


51. 


Suggestions  for  the  Teacher 


The  most  important  point  in  connection  with  the  study  of 
plants  is  to  train  the  powers  of  observation.  The  child  should 
learn  to  discriminate  between  plants.  While  important  to  know 
the  name  of  a  plant,  it  is  far  better  to  be  able  to  tell  what  the 
differences  are.  For  instance,  we  have  about  1100  different  kinds 
of  flowering  plants  in  the  state  of  Iowa.  They  differ  from  each 
other  by  one  or  more  characters.  The  student  should  learn  the 
most  important  differences.  To  illustrate,  we  have  in  Iowa,  two 
kinds  of  morning  glory,  one  the  common  bindweed  or  wild 
morning  glory,  native  to  Iowa,  with  flowers  from  one  to  two 
inches  long,  leaves  large  halberd,  or  arrow  shaped,  and  running 
rootstocks  often  called  "roots"  but  these  so-called  roots  have 
small  scales.  The  European  bindweed  has  much  smaller  flowers, 
less  than  one  inch  long,  leaves  small  ovate  and  arrow  shaped, 
and  running  roots,  no  scales  on  these. 

Many  people  do  not  know  that  we  have  two  kinds  of  dandelion 
in  the  state.  The  common  one  (Taxaxacum  officinale,)  olive  green 
seeds  and  coarsely  divided  leaves,  and  the  red-seeded  one  (Tar- 
axacum erythrospermum)  with  red  or  dark  brown  seed  and 
deeply  divided  leaves. 

There  are  eight  thistles  in  the  state,  all  of  these  are  easily 
distinguished  by  a  very  simple  key  which  I  will  insert  here  for 
convenience.  The  characters  are  all  very  obvious. 

A.  Perennial.     Plants  living  year  after  year. 

1.  Heads  large,  numerous. 

a.     Leaves  woolly  both  sides — Woolly  Thistle  (C.  can- 

escens,  N.  W.  la.) 
a.     Leaves  hairy  on  lower  surface — Field  Thistle  (C. 

discolor,  la.  general. 

2.  Heads  small.     Leaves  slightly  woolly  underneath — 

Canada  Thistle  (C.  arvense,  la.  general.) 

3.  Heads  large,  usually  1,  blooms  early — Prairie  Thistle — 

(C.  Hillii,  la.  general.) 

B.  Biennial.    Plants  form  flowers  the  second  season  and  then 
die. 

1.     Heads  with  numerous  sharp  spines.    Leaves  very  spiny 


— Bull  Thistle  (C.  lanceolatum,  la.  general.) 
2.     Head  not  spiny  but  sticky. 

a.     Leaves  not  hairy  or  sparingly ;  in  swamps — Marsh 

Thistle  (C.  muticum,  N.  la.  rare.) 
a.     Leaves  hairy  at  least  below. 

Heads  very  large ;  in  swamps — Iowa  Thistle —  ( C. 

iowense,  meadows,  la.  general.) 
Heads  smaller;  in  woods — Wood  Thistle  (C.  altis- 

simum,  E.  la.) 

The  C.  of  the  Sunflower  family  (Compositae),  stands  for  the 
genus  Cirsium,  which  includes  all  of  the  true  thistles.  There  are 
other  so-called  thistles  but  the  botanical  name  should  only  be 
applied  to  the  plants  of  this  genus.  The  Russian  thistle  is  not 
a  true  thistle  but  belongs  to  the  Goosefoot  Family  (Chenopo- 
diaceae. )  The  student  should  early  recognize  that  certain  plants 
belong  to  some  particular  family  and  with  a  little  practice  such 
plants  as  the  sunflower,  aster,  goldenrod,  purple  cone  flower, 
may  weed,  and  dandelion,  will  readily  be  recognized  as  belonging 
to  the  composite  family. 

To  facilitate  the  work  of  the  teacher  I  have  added  a  few  ques- 
tions which  the  student  should  answer.  If  the  teacher  is  not 
familiar  with  the  terms  that  are  here  used,  any  of  the  larger 
dictionaries  will  assist  in  getting  the  definitions,  sepals,  petals, 
stamens,  pistils,  bracts,  ray  flowers,  achene,  etc.  Simple  leaves 
may  be  linear,  hastate,  halberd,  cordate,  acute,  acuminate,  cleft, 
lobed,  dissected,  and  sagittate.  Compound  leaves  may  be  pin- 
nate (rose),  and  palmately  (horse  chestnut)  compound.  Fruits 
may  be  berry  (black  nightshade,  horse  nettle),  capsule  (Jimson 
weed),  pod  (clover  and  sweet  clover),  achene  (sunflower,  thistle), 
caryopsis  or  grain  fruit  (corn,  wheat,  crab  grass).  Flowers, 
regular  (morning  glory,  strawberry),  irregular  (sweet  clover, 
sweet  pea),  polypetalous  (crowfoot,  clover),  gameopetalous 
(morning  glory,  horse  nettle),  apetalous  (smartweed),  calyx  col- 
ored like  petals  (smartweed.) 

QUESTIONS  AND  TOPICS. 

1.  Describe  accurately  in  your  own  language  the  chief  points 
of  the  following  weeds:     Greater  or  giant  ragweed,  dandelion, 
quack  grass,  burdock,  velvet  weed,  dock,  parsnip,  cocklebur  and 
other  weeds  mentioned  in  the  Iowa  weed  law. 

2.  Note  the  methods  of  reproduction  in  the  following  weeds : 
Canada  thistle,  dock,  quack  grass,  foxtail,  burdock,  bull  thistle, 
cocklebur,  horse  nettle,  velvet  weed. 

3.  Note  the  difference  in  the  underground  parts  of  the  fol- 
lowing weeds:     Morning  glory,  quack  grass,  milkweed,  sheep 


53. 

sorrel.     Determine  whether  roots  or  underground  stems.     Are 
there  any  small  scales  present  on  the  underground  portions  ? 

4.  How  do  you  know  that  quack  grass  is  a  stem?     How  do 
you  know  that  milkweed  is  a  root? 

5.  Determine  the  duration  of  life  of  as  many  weeds  as  pos- 
sible.    For  example,  foxtail    (annual),  wild  barley  or  squirrel 
tail  grass  (winter  annual),  bull  thistle,  wild  carrot  and  burdock 
(biennial),  quack  grass,  Canada  thistle,  tanweed,  morning  glory 
(perennial.) 

6.  Determine  the  root  and  stem  character  of  as  many  weeds 
as  possible.     Determine  also  the  space  they  occupy  in  the  soil, 
whether  deep  or  shallow  rooted  and  how  these  roots  injure  the 
crops. 

7.  Determine  the  number  of  seeds  produced  by  some  indi- 
vidual weeds  and  make  a  record  of  the  result. 

8.  Now  determine  the  weed  seeds  produced  per  acre  of  some 
weed. 

9.  Make  a  study  of  the  following  weed  seeds :    Foxtail,  cockle- 
bur,  burdock,  plantain,  catnip,  ragweed,  dock,  smartweed,  butter 
print  or  velvet  leaf,  may  weed  or  dog  fennel,  mustard,  sweet 
clover,  dodder,  lambs  quarter,  buckhorn,  wild  carrot  and  pig- 
weed. 

10.  Why  are  weeds  detrimental  to  agriculture? 

11.  Determine  the  number  of  different  kinds  of  weeds  on  a 
given  area.     If  you  cannot  name  them  dry  the  specimens  and 
send  to  me  for  identification. 

12.  In  what  ways  do  weeds  spread?    Give  a  concise  account 
of  the  methods  and  give  illustrations  of  each. 

13.  What  weeds  are  scattered  by  the  wind,  water,  snow,  ani- 
mals and  explosive  properties. 

14.  Germinate  some  of  the  weed  seeds.    Determine  the  per- 
centage of  germination  and  study  the  characters  of  the  weed 
seedlings.    How  many  seeds  in  the  cocklebur  and  how  many  seeds 
germinate  the  first  season. 

15.  Try  to  germinate  the  seeds  of  some  weeds  immediately; 
take  another  lot  of  the  same  kind,  stratify  in  sand  or  earth  and 
allow  them  to  freeze.    Plant  the  seed  in  April.    If  you  find  any 
difference  determine  the  percentage  in  each  case. 

16.  Determine  the  percentage  of  impurities  in  clover  seed. 
Obtain  bulletin  115  of  the  Iowa  Agricultural  Experiment  Sta- 
tion which  gives  methods  in  detail.     This  bulletin  will  be  sent 
upon  application. 

17.  Make  a  collection  of  weeds  and  weed  seeds.     Specimens 
can  be  preserved  and  dried  for  reference. 


54. 

18.  Determine  the  kinds  of  weeds  found  in  the  following 
places :    The  corn  fields,  garden,  roadsides,  pasture  and  in  vacant 
lots,  door  yards  and  barn  yards. 

19.  After  these  points  have  been  carefully  studied  and  the 
habits  of  the  plants  determined,  suggest  a  method  of  extermina- 
tion of  weeds  studied. 

20.  Determine  the  yield  of  corn  or  other  crops  per  acre  in 
some  clean   fields  and  compare   them  with  some   weedy  fields. 
Which  fields  give  the  largest  yield. 

21.  Become  familiar  with  a   few  poisonous  plants  such  as 
poison  ivy,  which  is  frequently  a  climbing  plant,  jimson  weed, 
a  rank  smelling  herb  with  large  white  flowers,  the  cowbane  with 
clustered  roots  and  clustered  white  flowers  in  umbels  like  parsnip. 

BIBLIOGRAPHY. 

The  following  papers  and  books  may  be  used  for  reference: 

Pammel,  L.  H.  Some  weeds  of  Iowa.  Bull.  la.  State  College 
Experiment  Station,  Ames,  70.  Russian  thistle,  Bull.  26;  Quack 
and  Wheat  grasses,  Bull.  83;  Press  bulletins,  11,  12  and  13. 
These  may  be  had,  except  No.  70,  by  writing  Prof.  Curtiss,  Ames. 

Pammel,  L.  H.  and  Charlotte  M.  King.  Notes  on  Eradication 
of  Weeds  with  experiments  made  in  1907  and  1908.  Bull.  105. 
Iowa  Agricultural  Experiment  Station. 

Results  of  Seed  Investigations  for  1908  and  1909.  Bull.  115. 
See  also  Bull.  88  of  the  same  station  by  L.  H.  Pammel,  R.  E. 
Buchanan  and  Charlotte  M.  King.  Iowa  Agricultural  Experi- 
ment Station. 

Pammel,  L.  H.  Weeds  of  the  Farm  and  Garden.  Orange  Judd 
Co.,  New  York.  About  300  pages.  In  press. 

Floras  and  Manuals.     The  following  cover  our  territory. 

Britton.  Manual  of  the  Flora  of  the  Northern  States  and 
Canada.  Henry  Holt  &  Co. 

Robinson  and  Fernald.  Gray's  Manual  of  Botany  of  Northern 
United  States.  American  Book  Co. 

Clark,  Geo.  H.  &  Fletcher,  J.  Farm  Weeds  of  Canada.  Pub- 
lished by  the  Department  of  Agriculture,  Canada.  Price  $1.00. 

Htichcock,  A.  S.  &  Geo.  L.  Clothier.  Report  on  Kansas  Weeds. 
Bulls.  Kansas  Agricultural  Experiment  Station,  57;  80. 


Key  for  Families 


1.  Plants  grass-like. 

Stems  solid,  3  angled,  Cyperaceae  34 

Stems  hollow,  round  in  cross  section,  Gramineae  30 

2.  Plants  not  grass-like. 

Flowers  inconspicuous. 

Flowers  with  thin,  not  greenish  bracts,  Amaranthaceae  37 
Flowers  greenish,  succulent  herbs,  Chenopodiaccae  37 
Flowers  greenish,  3  sepals  enclosing  the  seed,  acrid  herbs, 

Polygonaceae  34 
Flowers  conspicuous. 

Succulent  plants,  Portulaceae  40 

Plants  not  succulent,  acrid,  sepals  petal-like, 

Polygonaceae  34 
Plants  not  succulent,  acrid,  sepals  and  petals  present, 

Ranunculaceae  40 
Plants  not  acrid. 

Stems  with  swollen  joints,  . .  Caryophyllaceae  37 

Stems  with  joints  not  swollen. 

Flowers  regular  of  separate  parts. 

Flowers  in  umbels,  Umbelliferae  42 

Flowers  not  in  umbels. 

Pungent  herbs,  6  separate  stamens, 

Cruciferae  40 
Bland  herbs,  stamens  in  one  set, 

Malvaceae  41 

Flowers  in  one  pie  ce,  Gamopetalous 
Flowers  irregular,  stem  4  angled,         Labiatae  47 
Flowers  regular,  stem  not  4  angled. 

Twining  plants,  Convolvulaceae  45 

Not  twining  plants. 

Conspicuous  flowers  not  in  heads. 

Fruit   a   berry,  Solanaceae  48 

Flowers  in  heads,  Compositae  49 

Flowers  inconspicuous. 

Plantgainaceae  49 


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